Jetpack is one of the most useful and popular plugins for WordPress. Its goal is to extend the services of WordPress.com onto self-hosted “WordPress.org” sites. It has tons of features. Among others, it offers an image CDN, related posts feature, free stat tracking, social sharing buttons and more.

Getting it set up is a little more complex than most other plugins though. You have to do that normal install and activate procedure, but then you must authenticate with WordPress.com. If you’ve ever used something like Facebook to log in on a different site, this is pretty similar. If not, watch the video which explains:

Authenticating Jetpack with WordPress.com to Unlock Its Features

1. 1. Go to “Plugins > Add New”.
2. Search for “Jetpack by WordPress.com”. “Install” and “Activate” the plugin.
3. You should immediately see a “Connect Jetpack to WordPress.com” screen. If you don’t, click to “Jetpack” near the top of your left sidebar.
4. On that screen, click the “Connect Jetpack to WordPress.com” button.
5. You will then be taken over to WordPress.com. If you’re not logged in to WordPress.com, you’ll be prompted for a username and password. Enter them. (If you are already logged in—I was in the video—you’ll skip this step.)
6. Click the “Approve” button after it appears.
7. You’ll probably be offered an “Upgrade” screen to pick your pricing tier. All the classic Jetpack features are still in the “Free” tier. But if you want Jetpack to do things like backups and more for you you can select a paid tier. (If you select one of those, you’ll be prompted for payment.)
8. Now you’ll configure Jetpack. You can either take the recommended setup, or turn individual features on one-by-one (the course I took in the video).

Further Reading on Jetpack

https://wpshout.com/quick-guides/enable-photon-free-jetpack-image-cdn/

Write WordPress Posts in Google Docs with Jetpack and a Chrome Extension