Gravatar, which stands for Globally Recognized Avatar, is a service owned by Automattic, the company behind WordPress. It allows users to create a universal avatar that can be used on any website that supports the Gravatar service, including WordPress.
When a user signs up for a Gravatar account on Gravatar.com, they can upload an image that will be associated with their email address. Then, whenever they leave a comment on a WordPress site or other site that supports Gravatars, their avatar will automatically appear next to their name.
Gravatars can be especially useful for WordPress site owners, as they can help to personalize comments and make it easier for readers to identify commenters. They can also be used in author boxes, user profiles, and other areas of a WordPress site where user avatars are displayed.
In WordPress, Gravatars can be enabled or disabled in the settings, and site owners can choose the default Gravatar image that will be displayed for users who do not have a Gravatar account. Additionally, users can customize their Gravatar settings and choose different images to use for different email addresses.