avatar from facebook

Joomla itself doesn't have a method to store avatars for users. They only have the User - Profile plugin which lets you save additional profile information for each user.

If you want to store the avatar for your users, you'll need to use another profile extension like EasySocial, JomSocial, Community Builder, etc.

I hope that helps explain, but if you have any other questions, just let me know.

Thanks,
Alex