Users in your forum can create Avatars and Signatures, if you allow it. Avatars are small images that get displayed along with the user’s name in posts and replies they make. Signatures are small pieces of text and/or an image that is displayed at the bottom of each post the user makes. Signatures often contain a link to the user’s site or a favorite quote. Avatars and Signatures are used throughout ExpressionEngine and are not specific to the forum.
To edit any of these settings you should visit the Membership Preferences General Configuration page. This can be found under Members > Preferences.
You can enable or disable Avatars and determine their settings in the Avatar Preferences section. Likewise, you can set up Signatures under the Signature Preferences section.
By default, Avatars and Signatures are disabled.