WordPress updates are always released when a security vulnerability is found. The WordPress update will contain the patch for the vulnerability which is why keeping a WordPress website updated is important.
WordPress updates are easily done by going to your WordPress dashboard clicking on your update tab. Once you are on the update page you will be to upload your WordPress website, plugins and themes.

Updating WordPress if you are not a web developer.
Updating a WordPress website is easy to do, BUT not always safe. Plugins crash and for other reasons you can experience different errors when updating your WordPress website. Errors that rise due to updating a WordPress can be temporarily fixed by keeping a back up of your WordPress website you can deploy if you do experience any problems updating WordPress on your own. A large or highly custom WordPress website should be updated by a developer.