ProfileStore is a wrapper for Roblox’s DataStoreService.
https://create.roblox.com/docs/reference/engine/classes/DataStoreService
ProfileStore has a few features that DataStoreService doesn’t have, namely session locking which prevents data loss due to two servers attempting to edit the same data at the same time.
It really depends on what you want to use, though ProfileStore streamlines data saving by a fair bit so I can recommend it.