Buddypress question on Full Name field


I have noticed that Buddypress in the profile page shows the username for the Full name in the users profile in the members section.

Can someone explain what the purpose of the full name is as I have looked around and can't see where it is used? I understand that a user can update the first and last name in their wp admin profile and select to use that instead of their username in their activity stream.

I'm confused about where the Full name fits in the scheme of things.