Simply put, a domain name is a name that is used to identify an address on the Internet for a particular Web site and any e-mail addresses configured for that site, such as http://www.bloggingdata.com and info@www.bloggingdata.com.
The Web address itself is composed of four distinct parts, as diagrammed in the figure below:
- Protocol: The first part of a Web address, http://, is the HyperText Transfer Protocol (HTTP), which identifies the protocol that allows a computer to browse the Web by getting information from a remote server. Secure access to the Internet (that is, anytime a domain has an SSL [Secure Sockets Layer] certificate installed on the host server for encrypting private data) requires the use of the https:// (note the s for secure) protocol.
- www: The second part refers to the World Wide Web and identifies the type of page that will be delivered in a browser window. You might notice that some sites still display in your browser without the www part of the address, such as typing just google.com into your browser’s address bar instead of www.google.com, but that function is typically server dependent and isn’t a universal feature of domain names. Another type of Web address includes domains where the www is omitted, such as in http://maps.google.com. This type of address refers to a subsite or subdomain that resides on the main domain’s servers but is separate from it.
- Domain name: The third part identifies the unique name of the Web site as registered by the owner of the site. Domain names may contain any combination of uppercase and lowercase letters and numbers. In addition, though less often used, domain names may also include hyphens but no other special characters.
- Extension: The fourth part identifies the type of site visitors should expect to see at the address, such as .com for commercial business sites, .org for nonprofit organizations, and .edu for educational sites.
Although several unrestricted domain extensions are in use by all kinds of businesses around the world, the most familiar extensions should really be used as they were intended. For example, the .org extension should be used for nonprofit organizations, and the .gov extension should be used exclusively for government agencies. The figure below lists the more common extensions from around the world.
James Cage is a self taught web blogger and developer. He is the founder of Blogging Inspiration. You can connect with him on twitter @ james_cage 
