Before you get started updating WordPress to the latest version, updating a plugin or even doing some small changes on your website, it’s a good idea to back up your website.
This means if there are any issues with the new version you can restore your website (install the old version).
Also, more importantly, backups can be critical for security. When a security vulnerability is discovered, you may need to fix and partially/complete restore.
Backups are a must-have for every type of website, but clients are often reluctant to handle this task themselves. They fear doing something wrong.