What are usernames?
You can customize the web address for your profile or Facebook Page by selecting a unique username. It will appear in the location bar of your browser after "https://www.facebook.com/" when you view your profile or Page.
A common example of a username is some variation on your name. For example, someone named Jane Doe might choose "jane.doe" for her username so her friends can visit her profile by going to www.facebook.com/jane.doe. Similarly, you can choose an extension for your Page web address that resembles your Page's name to make it easier for people to find you on Facebook (ex: https://www.facebook.com/facebooktips). Usernames are not the same as your name or Page name.
Learn how to customize your profile or Page web address.