What is an avatar? An avatar is the graphical representation of a user or a user's alter ego or character. It may take either a three-dimensional form, as in games or virtual worlds, or a two-dimensional form as an icon in Internet forums and other online communities.
Many web services and applications allow members and users to provide an avatar for additional visual identification of content they have created (e.g. posts, comments, etc.), in lists where they are included as part of a larger membership (e.g. user lists), or for items for which they have explicit permission (e.g. Google documents).
Managing avatars individually based on service is a real chore. Enter Gravatar.com. This service allows you to upload one or more avatars of yourself, and associate them with one or more e-mail addresses, creating a globally available avatar. Instantly, your avatar will be visible on comments you have posted, or in user lists, in services like WordPress.com or on any WordPress sites. Services like MailChimp support Gravatar.com, and there are even plugins for Google Chrome to add support to GMail and other services.