Many people confuse domain names with websites. Although related, they are 2 different things.
For our purposes, domain names are just that: Names. They may or may not point to/pull up a website. Each domain can only pull up one website. On the other hand, an unlimited of domains can all pull up the same site.
Some people buy/register multiple domains just to hold onto that name so no one else can use it, or for future use. Others, such as our own Padgett McFeely, use variations of a domain and have them all work with the same website. If someone spells Padgett's name wrong when typing it in the address bar (imagine that), they still land on her site. Check it out:
PadgettMcFeely.com
PadgetMcFeely.com
PadgettMcFeeley.com
PadgetMcFeeley.com
All of these domains point to / pull up the same site. The Main Domain is set to the correct spelling of her name. All the above open to the Main Domain, padgettmcfeely.com.
A website (site) however, is an online location connected to the internet via the web consisting of pages or web pages.
Also see our FAQ What a Domain Is ~ Why You Need One