Similar to Shrek, domain names have layers like an onion. To understand the layers, one should understand the fundamentals. Computers and servers have a unique IP address that consist of numbers and dots. A domain name simply points to an IP address.  The illustration below shows the parts of a domain.

http:// – http:// stands for Hypertext Transfer Protocol and acts as interpretation layer between web servers and web browsers.

URL – URL stands for Uniform Resource Locator and it’s the address of a webpage on the web.

TDL – TDL stands for Top-Level Domains. The most recognizable TDL is .com and resides in the generic category along with .net, .gov, .edu, etc. Country code is another catergory and offers .us, .ly, .es, .mp, etc.

SDL – SDL stands for Second-Level Domain and resides to the immediate left of the TDL. People customize this area for their needs such as company branding.

Sub-domain - In this instance the sub-domain represents a host server. The most recognizable host server is www. but sub-domains can be used to describe any subsection of a domain name, like blog.domain.com.

Directory – This is a directory for files or a representation of an action/method.

File name – This is the file that resides within the parent domain.