This is a very common question, so don't worry if you don't know what a domain name is. Essentially, a domain name is an address that points to your website.
What's Important About a Domain Name?
Your website is located on a server with a unique numerical address for locating it. However, the numerical address is arbitrary and not easy for people to remember when looking for your website. Unlike the numerical address, a domain name can be made up of letters and therefore words. People can easily find their way to your website by typing in your domain name.