A Gravatar is a “Globally Recognized Avatar”, which you can create when you open an account at Gravatar. It's a personal photo of you or anything else that appears next to a comment that you may have made on a WordPress website. That photo is known as an Avatar. You can only have your Avatar appear next to your name when you use an email address (to leave a comment) that's associated with your Gravatar account.
As you can see in the above example, two users left comments on a WordPress website and automatically the chosen profile photo was assigned to their Gravatar accounts. You probably have experienced this many times over on different WordPress websites, and even sites and blogs outside of WordPress. The question is, how do you use Gravatar on our own WordPress blog?
Default WordPress Integration
Gravatars have grown in popularity over the years, and these days it's very unlikely that a WordPress theme will not support Gravatars by default. The best and easiest way to make sure your site is running Gravatars is by going to Settings => Discussion in your WordPress dashboard, and once you scroll to the bottom of the page, you will see this settings panel:
From here it's very easy to decide on what kind of Avatars you want to use for your site, and whether you want to use them at all. It's worth remembering that there is still a tiny percentage of themes out there that might not support Gravatar images, but that is very unlikely. In such cases, it's best to look at 3rd party alternatives, such as the following WordPress plugin for utilizing social media avatars.
WP Social Avatar
For WordPress websites that are seriously community oriented, WP Social Avatar is a great plugin to switch away from Gravatar and instead utilize your profile pictures from social platforms such as Facebook, and Google Plus. The way this plugin works is that you have to assign a specific user role that can use the Social Avatar feature from the admin dashboard, and then use the actual Social Avatar settings page to set your custom social media avatar. It's definitely a lot more work than using Gravatar, but it can have its benefits; especially for thriving communities.