If you are running WordPress you’ll want to update the core software when an upgrade becomes available.
Upgrades are typically available once a month, sometimes even more often than that.
In most cases, you’ll see the upgrade notice at the top of your WordPress Dashboard when an upgrade becomes available. See screen-capture below.
Upgrades typically address security issues. They can also be performance related upgrades.
Whatever the case, it’s a good idea to keep your WordPress installation up-to-date.