What is a Gravatar and how to use it on WordPress?

A Globally Recognized Avatar

Your Gravatar is an image that follows you from site to site appearing beside your name when you do things like comment or post on a blog. Avatars help identify your posts on blogs and web forums, so why not on any site?

Visit Gravatar

How to Use Gravatars in WordPress

WordPress integrates Gravatars into every WordPress site. Once registered with Gravatar, the service matches your WordPress profile information to the email address registered with Gravatar and displays your custom Gravatar image next to comments and (optionally) elsewhere on the WordPress site. If you choose not to sign up with Gravatar, the default icon set by the Administrator appears next to your name.

Why use Gravatars?

Providing your users with avatars has become a convention in web-publishing. Enabling Gravatars on your WordPress site simplifies the process for everyone involved. While it is possible to use a WordPress Plugin to manage user avatars on your WordPress-run site, using Gravatars on your site makes less work for both you and your site’s users.

Benefits for Administrators

You can add user Gravatars with very little effort
You don’t need to maintain an additional Plugin
You don’t have to manage user accounts, or their images, for commenters to use Gravatars on your site
Benefits for Users
You don’t need to register for every site you visit just to use a Gravatar
You can update the Gravatar you use across multiple sites by uploading a single image in a single place

Using Gravatars on your Site

To start using Gravatars on your site:

• Log in as an administrator to your site
• Navigate to Settings > Discussion and scroll down to the “Avatar” Section
• The “Avatar” section presents you with several options:
  • Avatar Display: Toggle Gravatars on and off for your site.
    • Maximum Rating: When users create a profile on Gravatar, they are given the opportunity to rate their Gravatar image as G, PG, R, X based on its appropriateness. Select the radio button for the maximum rating you would like displayed on your site.
    • Default Avatar: WordPress allows for you to select what image you would like to display when a commenter does not have a Gravatar account. Selecting one of the “generated” icons give you and your users some of the benefits of a Gravatar without requiring them to have a Gravatar account. The icons that say “generated” next to them take the email of the commenter and link it to an auto-generated image. Now, every time that commenter posts to your site, they will have the same unique image next to their name.

Source: https://codex.wordpress.org/How_to_Use_Gravatars_in_WordPress