One of the major benefits of working with VMs is that you can easily take a snapshot, make a change, test out your change or changes, and if something goes horribly wrong, you can easily revert back your changes at a click of a button. Backup software also uses snapshots.
Great! Life is good and you don't have to worry too much if something goes wrong during an upgrade, Windows patching, installing new software, etc... assuming you took a snapshot before doing any major work on your VM or VMs.
Unfortunately, things aren't always so simple: Your VMware administrators take snapshots and then forget to delete them when all has tested OK. Or your backup software runs and, for a wide range of possible reasons, you are left with dozens of snapshots. Reality is that no one is perfect and neither is your software. And snapshots get left behind. You can delete them one by one, but that's too time-consuming and prone to issue by the user doing the clicking around, getting distracted, and missing a few snapshots that should have gotten cleaned up. That's were PowerCLI comes in to do the heavy lifting.
Awesome! But if it can clean up snapshots, can it also create them for you prior to major changes? Yes, of course.