Plugins are add-on pieces of software for WordPress that add new features and capabilities to your blog.
Plugins can do simple things, like changing how something is displayed on your site, or plugins can add vast new features to your blog like adding a membership site or selling products.
There are thousands and thousands of plugins available. Most of them are free and can be installed by clicking Plugins on the left menu of the admin dashboard, and the searching for plugins that do what you’d like.
Many plugins also offer paid premium versions that add even more features.
When you are looking for plugins it’s important to choose the ones that have a lot of active installs — over 10,000 installs is a good starting point — and have a lot of 4-star and 5-star reviews.
It’s also important to not install too many plugins. Each one adds a little bit of extra overhead to your WordPress site. Just use the ones you need to accomplish the goals you havbe for your site. If you stop using a plugin you should deactivate it and delete it.
I recommend starting with two free plugins on every WordPress site: All In One WP Security to help keep your site secure and Yoast SEO to help you write your content so it can be found in the search engines. Both of the may be installed by searching for them on the Plugins page in your WordPress admin dashboard.