KNOWLEDGE BASE

	What is Domain Name		ICANN
	Meaning of Top Level Domain		TCP / IP
	Tips for Domain Name choice		Web Hosting
	Domain Registrant & Renewal		Server
	Domain Transfer		Whois
	Domain Registry		I P Address
	Name Servers		FTP
	What is a Protocol		SMTP
	Cookies		Plug-in
	CGI Scripts

What is Domain name

A domain name is the text name corresponding to the numeric IP address of a computer on the Internet. A domain name must be unique. Internet users access your website using your domain name. download The process of copying files, information and images from the Internet to your computer. Every time a visitor accesses a page on the Internet, they are downloading the contents of that page.

It is also a unique name that identifies an Internet site. It is up to fifteen characters in length, but can now be up to sixty-seven characters, assigned to identify the domain on the network. A domain name must be different than all other domain names, workgroup names, and computer names on the network.

Domain is a method of identifying computer addresses. Your e-mail address has a domain address. If you have an "edu" at the end of your e-mail address that means your account is affiliated with an educational institution. A "com" extension means you have a business account. A government account has a .gov suffix.

Domain names are the human-readable addresses used on the Internet (eg, "www.microsoft.com"). The Domain Name Service translates these names into IP addresses which TCP/IP programs use directly. Compare dotted quad.

Meaning of TOP-LEVEL DOMAIN

TLD's (Top Level Domains) are the top level in the hierarchy of the Domain Name System. In the example "google.com" the ".com" is the Top Level Domain.
TLD's in general are often referred to as the Name space. For example the domain name domain.info is part of the .info name space.

Every other country has its own top-level domain, including ".us" for the U.S.A. Within the .us domain, there are subdomains for the fifty states, each generally with a name identical to the state's postal abbreviation. These are rarely used however. Within the .uk domain, there is a .ac.uk subdomain for academic sites and a .co.uk domain for commercial ones. Other top-level domains may be divided up in similar ways.

In the US and some other countries, the following top-level domains are used much more widely than the country code:

.com - commercial bodies
.edu - educational institutions
.gov - U. S. government
.mil - U. S. armed services
.net - network operators
.org - other organisations
Since the rapid commercialisation of the Internet in the 1990s the ".com" domain has become particularly heavily populated with every company trying to register its company name as a subdomain of .com, e.g. "netscape.com" so as to make it easy for customers to guess or remember the URL of the comany's home page.

United Nations entities use the domain names of the countries where they are located. The UN headquarters facility in New York City, for example, is un.org.

Tips on Domain name choice

Before buying your domain name, give some thought to the following:-

1) If possible use your sites name as the basis of your domain name e.g www.bit7informatics.com for Customised software and Website designing and development. This might seem common sense but not every site follows the convention. If you use your name in your URL it will be much easier for your customers to find you.

2) Generic names – if you can register a generic domain such as toys.com that’s great, but most of these have already gone. Also getting ranked in the search engines is likely to be harder. Selected a domain closer to your market segment will cut down the competition. E.g toyplanes.com

3) Hyphenated Names – Its easy to forget the hyphen! Which is the problem, particularly if your customer remembers your name but not your URL. Though on a positive note hyphenated names are less likely to be registered already.

4) If the .com or .co.in extension is not available then consider the alternative TLD ( Top level domain types) such as .net or .biz. If your domain name has already been registered then approach the owner and ask if they’ll sell. They may accept a £100. If you ask, they can only say no.

5) Plurals. Very often a domain name will be free in the plural but not in the singular form. It’s a personal choice, but if your prefered choice of domain name is not available you might be stuck.

6) Short or Long domains – A short domain name is more memorable, but less likely to be available. A longer domain is harder to remember, but can contain more keywords which is important as some of the search engines, use keywords in a domain name as part of the search algorithm.

7) Which Top Level Domain Type - .com, .co.in , .net etc This is a question I am often asked. There is no evidence that any domain name type is given preference by the search engines. However some search engines such as Google, have local searches e.g www.google.co.in which do select local content. Customer often get re-assurance from seeing a local TLD as they know they are dealing with a local company etc. You can, of course, register all of them!

8) Variations – If your prefered domain name is not available then its always worth trying a prefix my e.g mydomains.com or suffix e.g domains4U.com etc

Domain Transfer
The term 'transfer' has been used to describe various kinds of domain name transfers. Traditionally, simply changing the nameservers providing name service for a domain was considered a transfer. Nowadays, such a modification is more rightly called a modification, and the term 'transfer' describes the transfer of a domain from one registrar to another.

ICANN
The Internet Corporation for Assigned Names and Numbers (ICANN) is the non-profit corporation that was formed to assume responsibility for the IP address space allocation, protocol parameter assignment, domain name system management, and root server system management functions previously performed under U.S. Government contract by IANA and other entities.

For more information about ICANN, please visit: http://www.icann.org

Domain Registry
The 'Registry' is the system backend that is maintained by the operators of the TLD. Registrar's write new names to a central registry database, from which the authoritative root (essentially, a table of all domain names) is built. In the case of .com, .net and .org, the InterNIC runs the registry, and qualified registrars have shared access to it. In the case of many ccTLDs, the registry and registrar functions are combined within one entity.

Domain Registrant
A registrant is the person or company who registers a domain name. For example, Jessica Smith (registrant) registers the name jessicasmith.com through OpenSRS (registrar) who in turn writes the name to the central database (Registry).

Domain Renewal
Domains are leased on an annual basis, and need to be renewed once the current payment for the lease expires. If a domain is registered on April 15, 2003 and prepaid for one year, it will be due for renewal on April 15, 2004, at which point the registrant either pays for additional years, or lets the name expire. Domains can also be pre-paid for multiple years, up to a maximum of 10 years.

Domain Registrar
A "Registrar" (or "Domain Name Registrar") is an organization like Network Solutions that has control over the granting of domains within certain TLDs (top level domains, like the generic .com/.org/.net or country-specific .ca/.us/.mx etc.).

Name Servers
Nameservers (or Domain Name Servers) are the machines that perform the DNS function, containing zone files listing all the hosts on their network, and their corresponding IP addresses. If a nameserver is unable to determine which IP address a given hostname (i.e. www.opensrs.org) should map to, it will at least be able to point to another nameserver, which will either contain the information, or pass the request on until the correct nameserver is found.

Web Hosting
One service often closely associated with domain names is web site hosting. The World Wide Web is a massive collection of web sites, all hosted on computers (called web servers) all over the world. Because of the web's uniquely global nature, a web site should be accessible 24 hours a day, seven days a week. Rather than pay to have a 24/7 dedicated Internet connection to an in-house webserver, many people opt to host their sites with a web hosting provider. Web hosting clients simply upload their web sites to a shared (or dedicated) webserver, which the ISP maintains to ensure a constant, fast connection to the Internet.

WHOIS
WHOIS databases contain nameserver, registrar, and in some cases, full contact information about a domain name. Each registrar must maintain a WHOIS database containing all contact information for the domains they 'host'. A central registry WHOIS database is maintained by the InterNIC. This database contains only registrar and nameserver information for all .com, .net and .org domains.

Server

A server is a computer and/or a software package that provides requested information to clients. A server takes requests and returns information. It is there to serve information. When you are talking about a server, you could be referring to either the software or the hardware. There are different kinds of servers. A single hardware server could have several different types of server software packages running on it. Depending on the traffic, you could have a web server, FTP server, e-mail server, or chat server (to name a few) running on a single hardware server. The client that is requesting services must match the type of service that it is connecting to. There are different kinds of servers for both hardware and Software.Software - servers are available for web, e-mail, FTP, chat, IRC, and many others. Hardware - servers are available on many platforms UNIX, Mac, Windows 95/98, Windows NT, LINUX etc.

What is a Protocol

When computers communicate with each other, there needs to be a common set of rules and instructions that each computer follows. A specific set of communication rules is called a protocol. Because of the many ways computers can communicate with each other, there are many different protocols -- Some examples of these different protocols are HTTP, SMTP, FTP, IP, TCP etc.

I P Address

An IP Address is a "computers" return address. This return address is needed so the information you request will make it back to your computer.

Your IP (Internet Protocol) Address is a unique set of four numbers (0-255) that is always in the form of 255.255.255.255. Each computer hooked up to the internet has to have these numbers so that the requested information has a place to be delivered.

Some computers have a FIXED (static) number - in other words - ever time you turn on the computer you have the same numbers.

Your Internet Service Provider (ISP) probably has your IP Address associated to a Domain Name also. The Domain Name is not the IP Address but they are related. Take a look at the following information.

Now you see why they have both - the number for the computers and the name for us. (It is easier for us to remember.)

Your networks numbers are assigned by your Internet Service Providers (ISP) under authority of the Internet Assigned Numbers Authority (IANA) who in turn gets the numbering scheme from InterNic.

IP Addresses are sometimes referred to as dot addresses. The computer actually reads these as a set of 4 hexadecimal numbers (0-F). Since we live in a base 10 world, we convert these hexadecimal numbers to decimals and separating them by dots (.) which helps us to identify the 4 numbers. Without the dots it's hard to know if 1922435242 is 192.24.35.242 or 192.243.5.242 or even some other combination.

The IP address is usually expressed as four decimal numbers, each representing eight bits, separated by periods. This is sometimes known as the dot address and, more technically, as dotted quad notation. For Class A IP addresses, the numbers would represent "network.local.local.local"; for a Class C IP address, they would represent "network.network.network.local". The number version of the IP address can (and usually is) represented by a name or series of names called the domain name.

Relationship of the IP Address to the Physical Address

The machine or physical address used within an organization's local area networks may be different than the Internet's IP address. TCP/IP includes a facility called the Address Resolution Protocol (ARP) that lets the administrator create a table that maps IP addresses to physical addresses. The table is known as the ARP cache.

TCP / IP

TCP/ IP is a set of protocols that handles data transmitted across the internet.
TCP/IP (Transmission Control Protocol/Internet Protocol) works much like a piece of registered mail. You pack your valuable information - take it to the Post Office - they find the most efficient way to deliver it - send the package - get a signature stating that the item was received - return a message so that you are assured that the package arrived intact.
TCP/IP protocols break up the data into small segments called packets (this help with the transportation over the internet) , sends the address of where the information is to be sent, send the information, verify the receipt of the information and reconstruct the data on the other end.
The Internet is managed by the rules of sending and receiving information over TCP/ IP.

Reason for TCP :

The Internet Protocol (IP) works by exchanging groups of information called packets. Packets are short sequences of bytes consisting of a header and a body. The header describes the packet's destination, which routers on the Internet use to pass the packet along, generally in the right direction, until it arrives at its final destination. The body contains the application data.

In cases of congestion, the IP can discard packets, and, for efficiency reasons, two consecutive packets on the Internet can take different routes to the destination. Then, the packets can arrive at the destination in the wrong order.

The TCP software libraries use the IP and provide a simpler interface to applications by hiding most of the underlying packet structures, rearranging out-of-order packets, minimizing network congestion, and re-transmitting discarded packets. Thus, TCP very significantly simplifies the task of writing network applications.

FTP

File Transfer Protocol ( FTP) allows you to copy files from a remote computer to your own ( or vise-versa ).
FTP is an acronym for File Transfer Protocol. As the name suggests, FTP is used to transfer files between computers on a network, such as the Internet. You can use FTP to exchange files between computer accounts, to transfer files between an account and a desktop computer, or to access software archives on the Internet.

FTP is the simplest way to exchange files between computers on the Internet. Like the Hypertext Transfer Protocol (HTTP), which transfers displayable Web pages and related files, and the Simple Mail Transfer Protocol (SMTP), which transfers email, FTP is an application protocol that uses the Internet's TCP/IP protocols. FTP is commonly used to transfer Web page files from their creator to the computer that serves the pages to everyone on the Internet. It's also commonly used to download programs and other files to your computer from other servers.

SMTP

The network protocol used to send email across the Internet. Simple Mail Transport Protocol (SMTP) is the network protocol used to send email across the Internet. When you send email, its first stop is a server running SMTP.

SMTP service is the side of e-mail that allows clients to send outgoing e-mail messages to any valid e-mail address. The SMTP server performs two basic but important functions. First, it verifies that anyone attempting to send outgoing e-mail through the SMTP server has the right to do so. Secondly, it sends the outgoing mail and if undeliverable, sends the message back to the sender.

Cookie

Cookies contain information that is sent from a web server to a web browser. That information is stored on your hard drive. Some web sites record information that you have entered while at their site and send out cookies (text files) that are stored on your computer. This cookie is storing the name, count and last date entered on your hard drive. If you are using Netscape there should be a file on your hard drive named magic_cookie and it contains the following information. Internet Explorer has something similar.

Cookies DO NOT have access to your hard drive other that the original cookie file with the information that was sent. This file is then retrieved and updated by the server when you return to their site. Cookies are usually set to expire after a certain amount of time.

The main purpose of cookies is to identify users and possibly prepare customized Web pages for them. When you enter a Web site using cookies, you may be asked to fill out a form providing such information as your name and interests. This information is packaged into a cookie and sent to your Web browser which stores it for later use. The next time you go to the same , your browser will send the cookie to the The server can use this information to present you with custom Web pages. So, for example, instead of seeing just a generic welcome page you might see a welcome page with your name on it.

CGI Scripts

CGI (Common Gateway Interface) scripts are programs that run on the servers. The programs can vary in their complexity and design. CGI scripts are one way to maintain statistics on everything that happens on your web site. You have to be able to create a cgi-bin directory on your web site and have to have permissions required to execute these programs.

CGI scripts will directly interact with the server, where your whole web site resides, simply they are server-side. It works from your server you can take control over the scripts which are running by using other server files, for example the sendmail program of Unix. Javascripts don't access any of your other files, (for example you cannot access a database which is in your server). Javascripts are simply inserted into your HTML pages, which can be run by the browser.

Plug-in

A plug-in is a link to an external application that handles embedded information in a web page. A plug-in is a computer program that interacts with a host application (a web browser or an email client, for example) to provide a certain, usually very specific, function "on demand". Applications support plugins for many reasons. Some of the main reasons include: enabling third-party developers to create capabilities to extend an application, to support features yet unforeseen, to reduce the size of an application, and to separate source code from an application because of incompatible software licenses.