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UNIT- I Internet Basics: Basic concepts, communication on the internet, internet domains, internet server identities, establishing connectivity on the internet, client IP address, A brief overview of TCP/IP and its services, transmission control protocol, web server, web client, domain registration. Introduction to HTML: HTML, HTML tags, commonly used HTML commands, text formatting, text style, lists, adding graphics to HTML documents, tables, linking documents, frames, Forms, Image Maps. BASIC INTERNET CONCEPTS The ARPANET started with four nodes in 1969 and grew to just under 600 nodes before it was split in 1983. Internet was started with ARPANET. The NSFNET also started with a modest number of sites in 1986. After that, the network experienced literally exponential growth. Internet growth between 1981 and 1991 is documented in "Internet Growth (1981-1991)". The Internet is essentially a global network of computing resources. You can think about the Internet as a physical collection of routers and circuits as a set of shared resources or even as an attitude about interconnecting and intercommunication. The Internet is a global collection of computer networks that are linked together by devices called routers and use a common set of protocols for data transmission known as TCP/IP (transmission control protocol / Internet protocol). The primary purpose of the Internet is to facilitate the sharing of information. There are many different tools used on the Internet to make this possible. Some of the more common tools include email, list servers, newsgroups, telnet, gopher, FTP, and the World Wide Web. Probably the most popular of all Internet tools is the World Wide Web. The internet consists of two types of computers Servers and Clients Computers which offer information to be read are called Servers Computers that read the information offered are called Clients Servers run special software (Web Server Software) that allows them to Respond to Client requests for information Accept data from Clients Internet Based Services: Some of the basic services available to Internet users are: Email: A fast, easy, and inexpensive way to communicate with other Internet users around the world. Telnet : Allows a user to log into a remote computer as though it were a local system. FTP: Allows a user to transfer virtually every kind of file that can be stored on a computer from one Internet-connected computer to another. UseNet news : A distributed bulletin board that offers a combination news and discussion service on thousands of topics. World Wide Web (WWW): A hypertext interface to Internet information resources. This stands for World W ide W eb. A technical definition of the World Wide Web is : all the resources and users on the Internet that are using the Hypertext Transfer Protocol (HTTP). A broader definition comes from the organization that Web inventor Tim Berners-Lee helped found, the World Wide Web Consortium (W3C): The World Wide Web is the universe of network-accessible information, an embodiment of human knowledge.
In simple terms, The World Wide Web is a way of exchanging information between computers on the Internet, tying them together into a vast collection of interactive multimedia resources. The WWW is a collection of Internet sites that can be accessed by using a hypertext interface. Hypertext documents on the web contain links to other documents located anywhere on the web. By clicking on a link, you are immediately taken to another file or site to access relevant materials. The interesting thing about Hypertext links is that the links might take you to related material on another computer located anywhere in the world, rather than just to a file on your local hard drive. The Internet is not the World Wide Web - nor is it web browsing. This is a common misconception. Often people will say such things as, "OK, I am finished with email. Now I want to use the Internet." Email is something you can do over the Internet - as is web browsing with Netscape or Internet Explorer. In other words, the Internet is a collection of computers, networked together throughout the world, and communicating with each other through a common language called TCP/IP (Transfer Control Protocol/Internet Protocol). The various programs you use recognize TCP/IP, and if everything is set up correctly, and the computer is correctly connected to the Internet, all sorts of things can be done, including: Web Crossing email the World Wide Web (WWW) FTP Internet news All sorts of other services Basic WWW Concepts A. BROWSER -- A WWW browser is software on your computer that allows you to access the World Wide Web. Examples include Netscape Navigator and Microsoft Internet Explorer. Please know that a browser can’t work its magic unless you are somehow connected to the Internet. At home, that is normally accomplished by using a modem that is attached to your computer and your phone line and allows you to connect to, or dial-up, an Internet Service Provider (ISP). At work, it may be accomplished by connecting your workplace’s local area network to the Internet by using a router and a high speed data line. B. HYPERTEXT AND HYPERMEDIA -- Hypertext is text that contains electronic links to other text. In other words, if you click on hypertext it will take you to other related material. In addition, most WWW documents contain more than just text. They may include pictures, sounds, animations, and movies. Documents with links that contain more than just text are called hypermedia. C. HTML (HYPERTEXT MARKUP LANGUAGE) -- HTML is a set of commands used to create World Wide Web documents. The commands allow the document creator to define the parts of the document. For example, you may have text marked as headings, paragraphs, bulleted text, footers, etc. There are also commands that let you import images, sounds, animations, and movies as well as commands that let you specify links to other documents. If you wanted to create your own web page, you would need to know HTML or be able to use a tool that can generate HTML such as Claris Homepage or Adobe Page Mill.
When you register a Web address, also known as a domain name, such as tutorialspoint.com you have to specify the IP address of the Web server that will host the site. We will see different type of Web servers in a separate chapter. Web Browser Web Browsers are software installed on your PC. To access the Web you need a web browsers, such as Netscape Navigator, Microsoft Internet Explorer or Mozilla Firefox. Currently you must be using any sort of Web browser while you are naviating through my site tutorialspoint.com. On the Web, when you navigate through pages of information this is commonly known as browsing or surfing. We will see different type of Web browsers in a separate chapter. SMTP Server This stands for S imple M ail T ransfer P rotocol Server. This server takes care of delivering emails from one server to another server. When you send an email to an email address, it is delivered to its recipient by a SMTP Server. ISP This stands for I nternet S ervice P rovider. They are the companies who provide you service in terms of internet connection to connect to the internet. You will buy space on a Web Server from any Internet Service Provider. This space will be used to host your Web site. HTML This stands for H yper T ext M arkup L anguage. This is the language in which we write web pages for any Website. Even the page you are reading right now is written in HTML. This is a subset of Standard Generalized Mark-Up Language (SGML) for electronic publishing, the specific standard used for the World Wide Web. Hyperlink A hyperlink or simply a link is a selectable element in an electronic document that serves as an access point to other electronic resources. Typically, you click the hyperlink to access the linked resource. Familiar hyperlinks include buttons, icons, image maps, and clickable text links. DNS DNS stands for D omain N ame S ystem. When someone types in your domain name, www.example.com, your browser will ask the Domain Name System to find the IP that hosts your site. When you register your domain name, your IP address should be put in a DNS along with your domain name. Without doing it your domain name will not be functioning properly. W3C This stands for W orld W ide W eb C onsortium which is an international consortium of companies involved with the Internet and the Web. The W3C was founded in 1994 by Tim Berners-Lee, the original architect of the World Wide Web. The organization's purpose is to develop open standards so that the Web evolves in a single direction rather than being splintered among competing factions. The W3C is the chief standards body for HTTP and HTML.
Communication on the Internet English - the universal language on the Internet TCP/IP is the only protocol used to send data on the Internet. It is two individual sections; TCP a set of communication protocol and IP a unique address. Every machine connected to the internet must have an address by which it can be located on the internet. This is called the IP address of the machine. The internet is a network of networks. It is a governing body, which allocated unique IP addresses to organization lined to the internet. An international body “InterNIC”, is responsible for registering and assigning unique IP addresses to organizations wishing to manage networks, which will be part of the organization. A unique IP address points to an actual computer connected via a gateway to the internet. The computer is known as a Domain i.e. a place where information is available. This is a Physical Domain on the internet. When a web site provides internet clients information to read the site is mount as a Virtual Domain on an Internet Server. Special Guidance for Using the Internet as a Communication Tool The primary advantages of using the Internet as a communication tool are the flexibility and ease it provides. Hence, little is needed in the way of guidance for email and instant messaging. However, here are a few basic guidelines for using email : Respond quickly Be concise Make the main point at the start of the email
purpose. .org Originally designated for use by nonprofit organizations and individuals, now it can be used for any purpose. .net Originally designated for use by network organizations (such as Internet providers). Now it can be used for any purpose. .gov For governmental organizations. .mil For military organizations. .edu For four-year degree-granting colleges and universities only.
- Some Geographic Based Domains (Country code top-level domains) .jp The Japan domain .us The U.S. domain .ca The Canada domain .to The Tonga domain .in India Some geographic domains, such as the .to (Tonga) domain, open up their domains and make them available to anybody in the world. One common misconception is that ".com" is a domain for companies located in the U.S. It isn't - any company in the world can use a .com domain. A "host" refers to a fully specified domain, specified completely down to the specific machine and complete IP address. For example, webxharbor.com is a sub-domain of the .com domain. www.webharbor.com is the name of the web server machine in the webxharbor.com domain. It has a corresponding IP address, but you do not need to know it because the domain name system keeps track of it for you. When the Internet first started out there was just one big list with all the hosts in the world and their corresponding IP addresses. But the list quickly got too large and these days the same task is accomplished with the use of a distributed DNS (domain name server) system, components of which are located on most networks throughout the world (including the Web Crossing Harbor office).
Internet server identities
Internet Identity , or IID , is a privately held Internet security company based in Tacoma, Washington, USA. It primarily provides anti-phishing, malware and domain control security services to financial service firms, e-commerce, social networking and Internet Service Provider (ISP) companies. Microsoft uses IID as a data feed for its anti-phishing software as well as a partner in their Domain Defense Program. Other customers include BECU (Boeing Employees’ Credit Union), Monster.com and Yakima Valley Credit Union.
Identity: The complete set of characteristics that define you Identifier: A way of referring to set of characteristics An identifier is one or more pieces of data that uniquely identify a person or thing, within a given population. For example, your name or phone number, the IP address of your computer, or the MAC address of your computer’s network adapter. Service providers use identifiers to point to the other information they hold about you - what we have described as a ‘partial identity’. This allows them to build up a profile, over time, of you and the interactions you have with them. HTTP Server Identification: As stated above, and as shown in the sample screen shot above, ID Serve can almost always identify the make, model, and version of any web site's server software. This information is usually sent in the preamble (introduction) of replies to web queries, but it is not shown to the user. Non-HTTP Server Identification: Most non-HTTP (non-web) Internet servers (like FTP, SMTP, POP, NEWS, etc.) are required to transmit a line containing a numeric status code and a human readable greeting to any connecting client. So ID Serve can also connect with non-web servers to receive and report that server's greeting message. This generally reveals the server's make, model, version, and other potentially useful information. Reverse DNS Lookup: As shown in the image above, most ID Serve users will enter a site's or server's domain name or URL. ID Serve will then use the domain name system (DNS) to determine the IP address for that domain. But sometimes it's useful to go in the other direction to determine the domain name associated with a known and provided IP. This process, known as "reverse DNS lookup", is also built into ID Serve. Simply enter any IP address and ID Serve will attempt to determine the associated domain name. Additional applications for ID Serve: Simple Cookie Scout: If you are curious about the appearance, format, expiration, and use of a web site's browser cookies, ID Serve can be a convenient way to examine a web site's cookies without either providing or accepting that site's cookies. Simply scroll back through the "Server query processing" window to examine the "Cookie:" header lines sent by the site's web server. Simple Port Probe: ID Serve uses the standard Windows TCP protocol when attempting to connect to a remote server and port. Just like our ShieldsUP! port probe, ID Serve will display either connection success (an open port), or connection failure. In the event of a connection failure, ID Serve determines and displays whether the port is closed or stealth. ID Serve can, therefore, be used as a simple probe of any port on any remote machine.
How to Set Up an Internet Connection
The protocol used to setup communications between a Client and Server on the Internet is TCP/IP. TCP/IP, expands to read T ransmission C ontrol P rotocol / I nternet P rotocol. TCP/IP is a connection independent protocol.
- Set up the internet connection. Your internet service provider should have supplied you with a list of information necessary to establish a connection. For example, you will need to provide a login name and password (different from those you may have used to log into the modem itself); these are usually the email address and password you created when signing up for service through your service provider. If you are setting up a wireless connection, you may need to provide it with a name (which will make it easy to recognize when viewing the list of available wireless networks as you try to get online), login password (unless you live in a very remote area, a wireless network should always require a password from whoever is trying to connect to it, i.e. possibly your neighbors’ kid), and security options (WEP, WPA- PSK, etc.). Call your internet service provider to fill you in on any of your connection details if necessary.
- Save your settings. When the setup is complete, save the settings. The “internet” light on your modem should turn green to indicate that you are online. Common Modem and Router IP Addresses Alcatel SpeedTouch Home/Pro – 10.0.0.138 (no default password) Alcatel SpeedTouch 510/530/570 – 10.0.0.138 (no default password) Asus RT-N16 – 192.168.1.1 (default password admin) Billion BIPAC-711 CE – 192.168.1.254 (default password “admin”) Billion BIPAC-741 GE – 192.168.1.254 (default password “admin”) Billion BIPAC-743 GE – 192.168.1.254 (default password “admin”) Billion BIPAC-5100 – 192.168.1.254 (default password “admin”) Billion BIPAC-7500G – 192.168.1.254 (default password “admin”) Dell Wireless 2300 router – 192.168.2.1 (final .1 is fixed) D-Link DSL-302G – 10.1.1.1 (Ethernet port) or 10.1.1.2 (USB port) D-Link DSL-500 – 192.168.0.1 (default password "private") D-Link DSL-504 – 192.168.0.1 (default password "private") D-Link DSL-604+ – 192.168.0.1 (default password "private") DrayTek Vigor 2500 – 192.168.1. DrayTek Vigor 2500We – 192.168.1. DrayTek Vigor 2600 – 192.168.1. DrayTek Vigor 2600We – 192.168.1. Dynalink RTA300 – 192.168.1. Dynalink RTA300W – 192.168.1. Netcomm NB1300 – 192.168.1. Netcomm NB1300Plus4 – 192.168.1. Netcomm NB3300 – 192.168.1. Netcomm NB6 – 192.168.1.1 (default username "admin," default password "admin") Netcomm NB6PLUS4W – 192.168.1.1 (default username "admin," default password "admin," default WEP key "a1b2c3d4e5") Netgear DG814 – 192.168.0. Netgear DGN2000 – 192.168.0.1 (default username “admin,” default password “password”)
Web Excel PT-3808 – 10.0.0. Web Excel PT-3812 – 10.0.0. IP Addresses To identify all the computers and other devices (printers and other networked peripherals) on the Internet, each connected machine has a unique number, called an "IP address". IP stands for "Internet Protocol," the common language used by machines on the Internet to share information. An IP address is written as a set of 4 numbers, separated by periods, as in 203.183.184. An IP address is a numerical identification that is assigned to devices participating in a computer networks utilizing the IP for communication between its nodes. They are usually displayed in human readable form such as 192.168.100.1 (for IPv 4 ). IPv 4 uses 32-bit (4-bytes) addresses which limits the address space to 4294967296 (2^32 ) possible unique addresses. IPv 4 addresses are usually represented in dotted-decimal notation (four numbers, each ranging from 0 to 255, separated by dots, e.g. 147.132.42.18. This representation is sometimes referred to as dotted-octet representation of an IP address. Here is some simple mathematics you should know! Each number in this four-number address can range from 0 through 255. So there are 256 different possible numbers for each part. Since there are four parts, so there are a possible 256 X 256 X 256 X 256 = 256 to the 4th power = 4,294,967,296 different possible machine numbers - over four billion different possible machine numbers. One single network, for example, might typically have all the IP addresses starting with 203.183.184 (203.183.184.0 through 203.183.184.255). This has been a customary way of distributing IP numbers - in chunks of 256 addresses. This is referred to as a "Class C" network. If numbers are distributed as Class C networks it means there are only a possible 256 to the 3rd power different networks - or just 16 million networks - in the whole world. Many networks don't even use all the 256 IP addresses available to them, which mean that although the IP addresses are reserved by them they are going to waste. To help solve this problem, networks have started being assigned with just 8 or 16 IP addresses. But basically need a fixed, predefined IP address assigned to each machine that acts as a server to the outside world. You can get an IP address assignment from your network administrator, who receives them in turn from your network's Internet provider.
Servers
A server is just a host that serves something. Some examples are: FTP servers - People connect to them for file transfer, using a browser or a specialized FTP program, such as Fetch (on a Mac) or FTP Explorer (on Windows). Mail servers - People connect to them to send and receive mail, using such programs as Eudora, Netscape Mail, Claris Mail and Microsoft Outlook Express. Web Crossing - a server that lets users create and use online communities, including forums and chat and other services Web servers - A web server is simply a computer program that dispenses web pages as they are requested. The machine the program runs on is usually also called a server computers that serve web pages. People connect to web servers using browsers, such as Netscape Navigator or Internet Explorer. Summarize their functionality are They need to provide HTML pages (with the MIME type header).
The Structure of an Internet Address The structure of an Internet Server’s address keyed into a Client’s browser software is as follows: http://www.microsoft.com Where; http is the communication protocol to be used, www is the notation for World Wide Web, microsoft is the registered Domain Name associated with the IP address of an Internet server, and .com the Server provides commercial services to Clients who connect to it. To help speed up access, its IP address can be directly used, i.e. 127. 57. 13. 1 instead of the domain name, miscrosoft. com. In this case no name resolution needs to take place. There are occasions when you may need to get the remote address of the client requesting resources from your application.
- There are two ways of getting the client IP address of requests if we are running (1)Drupal ( Drupal is a i free and open-source content-management framework or content management system (also referred to as CMS), Meaning Drupal is used to manage content on informational sites, social media sites, member sites, intranets and web applications). (2) On Pantheon (a group of famous or important peoples.):
- System environment variable $_SYSTEM["REMOTE_ADDR"]. One benefit is that on Pantheon this takes into account if the X-Forwarded-For header is sent in cases when a request is filtered by a proxy.
- Use Drupal’s ip_address() function. The function leverages the $_SYSTEM["REMOTE_ADDR"] variable to get the client IP as well as parse other meta information like the remote proxy I.P (if available), trims the forwarded IPs if they contain any additional commas or spaces and filter out any untrusted IPs. When planning your strategy for remote address parsing it is important to note that this is not foolproof as clients may visit your site or application through a proxy that does not specify the correct headers. Therefore, be aware that this is not 100% reliable. What is a Domain? A Domain Name is like an identification name which is there to indicate the ownership to that name on the web. It is a unique address through which your customers and friends find all the information about your services or about you. Domain registration means choosing and registering one unique keyword for your website. Basically, website contains two major things, namely: domain name, the unique name that given to your site, the web contents, the pages and images.Once the website contents are ready, it will be necessary to do website domain registration. Nowadays register domain name is very simple process and it is very essential to have a website online. Once a Domain Registration is done under your name it cannot be used by any other user. This becomes your permanent address and users can have access to all the information no matter where you are located. Domain Names are also known as hostnames and each
domain has a suffix attached to it. The most common are .com, .net, .co, co.in, .org and others. FREE Domain Name, NO ADS! Free URL Redirection with Free Short Url Basic Free Domain Name Package: Let's list the most important FEATURES of this package here:
- Free Domain Name - www.yourname.co.nr that is a free subdomain name of .co.nr domain
- Free Short URL - we provide one of the shortest free web address on the net.. What can be shorter than a domain name? - Only a free domain name
- Free URL Redirection also known as free URL forwarding or domain forwarding service to redirect your free domain name to your real website address
- Free URL Cloaking also known as Free URL Masking - is used to mask a real website address with the Free Domain Name. So, your free domain name will always be in the location bar of your website visitors' web browser.
- Free Path Forwarding for both subdirectories and files. Path forwarding can be used if you want to access e.g. a subdirectory or some files using your free domain name forwarding address - e.g. http://www.domain.co.nr/forums/
- META TAGS support - the most important meta tags such as Title, Description, Keywords, Robots, and many other meta tags are supported - they are very important for your website to be indexed by search engines.
- Favicon support - add your very own Favicon / shortcut icon to your free shorter URL address in order to arrange personalized bookmarks for your web site.
- Google Webmaster Tools - support, that means you can now add your free .co.nr domain to Webmaster Tools using " google-site-verification " meta tag.
- Bing Webmaster Tools - support, i.e. now you can add your free .co.nr site to Bing Webmaster Tools using " msvalidate.01 " site verification metatag.
- No banners & No Popups , actually, NO ADS at all - and we are not going to add them in future. Enjoy our free and banner free service! 11.and much, much more
TCP/IP Protocol Architecture Model
TCP/IP is a collection of protocols, applications and services. The protocols is TCP/IP more data from one network layer to another. The OSI model describes idealized network communications with a family of protocols. TCP/IP does not directly correspond to this model. TCP/IP either combines several OSI layers into a single layer, or does not use certain layers at all. The following table shows the layers of the Oracle Solaris implementation of TCP/IP. The table lists the layers from the topmost layer (application) to the bottommost layer (physical network). Table 1-2 TCP/IP Protocol Stack OSI OSI Layer TCP/IP Layer TCP/IP Protocol Examples
IP addressing – The IP addressing conventions are part of the IP protocol. Designing an IPv4 Addressing Scheme introduces IPv4 addressing and IPv6 Addressing Overview introduces IPv6 addressing. Host-to-host communications – IP determines the path a packet must take, based on the receiving system's IP address. Packet formatting – IP assembles packets into units that are known as datagrams. Datagrams are fully described in Internet Layer: Where Packets Are Prepared for Delivery. Fragmentation – If a packet is too large for transmission over the network media, IP on the sending system breaks the packet into smaller fragments. IP on the receiving system then reconstructs the fragments into the original packet. Administering a TCP/IP Network (Tasks) contains more information on Oracle Solaris commands that use ICMP for error detection.
4. Transport Layer The TCP/IP transport layer ensures that packets arrive in sequence and without error, by swapping acknowledgments of data reception, and retransmitting lost packets. This type of communication is known as end-to-end. Transport layer protocols at this level are Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and Stream Control Transmission Protocol (SCTP). TCP and SCTP provide reliable, end-to-end service. UDP provides unreliable datagram service. TCP Protocol TCP enables applications to communicate with each other as though they were connected by a physical circuit. TCP sends data in a form that appears to be transmitted in a character-by- character fashion, rather than as discrete packets. This transmission consists of the following: Starting point, which opens the connection Entire transmission in byte order Ending point, which closes the connection. TCP attaches a header onto the transmitted data. This header contains many parameters that help processes on the sending system connect to peer processes on the receiving system. TCP confirms that a packet has reached its destination by establishing an end-to-end connection between sending and receiving hosts. TCP is therefore considered a “reliable, connection- oriented” protocol.
5. Application Layer The application layer defines standard Internet services and network applications that anyone can use. These services work with the transport layer to send and receive data. Many application layer protocols exist. Without this layer the computer and its working is problematic The following list shows examples of application layer protocols: Standard TCP/IP services such as the ftp, tftp, and telnet commands UNIX “r” commands, such as rlogin and rsh Name services, such as NIS and the domain name system (DNS) Directory services (LDAP) File services, such as the NFS service Simple Network Management Protocol (SNMP), which enables network management Router Discovery Server protocol (RDISC) and Routing Information Protocol (RIP) routing protocols
Standard TCP/IP Services
The World Wide Web is a worldwide information service on the Internet. The World Wide Web or the Web, as it is popularly known, uses special software called a Browser (client) and TCP/IP, HTTP and a Web Server to function. TCP/IP is the communication protocol used by the Internet and is a must for the World Wide Web to function. HyperText Transfer Protocol or HTTP is the protocol used by the WWW service to make communication possible between a Web Server and a Web Browser. A Web Server is special software, which runs on a computer and responds to requests made by other computers on the network. A Web Browser is simply an application program, which sends request to a Web Server and accepts a response to that request from the Web Server. FTP and Anonymous FTP – The File Transfer Protocol (FTP) transfers files to and from a remote network. FTP is not just a protocol but also a service and an application. FTP is especially useful for transferring files between different computers or FTP provides the facility to transfer files between two computers running on different operating systems such as UNIX, MS-DOS and Windows. The protocol includes the ftp command and the in.ftpd daemon. FTP enables a user to specify the name of the remote host and file transfer command options on the local host's command line. The in.ftpd daemon on the remote host then handles the requests from the local host. Unlike rcp, ftp works even when the remote computer does not run a UNIX based operating system. A user must log in to the remote system to make anftp connection, unless the remote system has been configured to allow anonymous FTP.
DNS – The domain name system (DNS) is the name service provided by the Internet for TCP/IP networks. DNS provides host names to the IP address service. DNS also serves as a database for mail administration. For a complete description of this service, see System Administration Guide: Naming and Directory Services (DNS, NIS, and LDAP). See also theresolver (3RESOLV) man page. /etc files – The original host-based UNIX name system was developed for standalone UNIX machines and then adapted for network use. Many old UNIX operating systems and computers still use this system, but it is not well suited for large complex networks. NIS – Network Information Service (NIS) was developed independently of DNS and has a slightly different focus. Whereas DNS focuses on making communication simpler by using machine names instead of numerical IP addresses, NIS focuses on making network administration more manageable by providing centralized control over a variety of network information. NIS stores information about machine names and addresses, users, the network itself, and network services. NIS name space information is stored in NIS maps. For more information on NIS Architecture and NIS Administration, see File Services The NFS application layer protocol provides file services for Oracle Solaris. You can find complete information about the NFS service in System Administration Guide: Network Services.
How do we use the Internet?
Email WWW, hypertext, browsers RSS FTP, P2P file distribution Mobile Internet IM, IRC, Skype Blogging, micro blogging Gaming Learning Video Conferencing Remote Backup Streaming video and audio Collaboration-Participation (Wiki) Collaborative tagging Software over the web Rich User Experiences Social networks Business and finance
HTML
Brief HTML Background
HTML is an abbreviation of "HyperText Mark-up Language" Hyper is the opposite of linear. When the program had executed one action it went to the next line and after that, the next line and so on. But HTML is different - we can go wherever you want and whenever you want. For example, it is not necessary to visit MSN.com before you visit HTML.net. Text is self-explanatory. Mark-up is what you do with the text. You are marking up the text the same way you do in a text editing program with headings, bullets and bold text and so on. Language is what HTML is. It uses many English words. So HTML is a markup language for describing web documents (web pages). HTML stands for H yper T ext M arkup L anguage A markup language is a set of markup tags HTML documents are described by HTML tags Each HTML tag describes different document content A markup language as it relates to browsers is a language with specific syntax that gives instructions to a web browser about how to display a page. HTML uses a pre-defined set of elements to identify content types. Elements contain one or more "tags" that contain or express content. Tags are surrounded by angle brackets, and the "closing" tag (the one that indicates the end of the content) is prefixed by a forward slash. The paragraph element consists of the start tag "
" and the closing tag "
". The following example shows a paragraph contained within the HTML paragraph element but remember it will not preserve more than one white spaces:
You are beginning to learn HTML.
HTML gives authors the means to: Publish online documents with headings, text, tables, lists, photos, etc. Retrieve online information via hypertext links, at the click of a button. Design forms for conducting transactions with remote services, for use in searching for information, making reservations, ordering products, etc. Include spread-sheets, video clips, sound clips, and other applications directly in their documents.
Web Pages
Web pages are created using HTML syntax. these pages must be organized and stored at a central computer. The organization of web pages into directories and files stored on the HDD of a central computer is called web site creation. Computers, which store web pages in the form of directories and files and provide these files to be read, are called servers. They act like service providers that service the need for information. Web server software that allows:- Web site management
