Maybe you are newer to git, but this does not feel like a good faith comment, because “restore” is a command that was added specifically because people complained that the overloading of “checkout” is confusing.
Anyway: “reset” changes the ref to which the HEAD branch points, and depending on options can also update the index and working tree to match as well. “Revert” creates a commit that is the reverse of an earlier commit. Restore rolls back uncommitted changes to a file.
What definition of hard are you using? It's an industrial strength tool used almost exclusively by professionals and expert-level amateurs. It's definitely hard, the same way knowing what to do with a welding machine is hard.
On the other hand, even among the professionals it has a reputation for being tricky and frustrating. Which is not the norm for most critical daily-use tools in this or any professional. So I'd also consider it hard in that sense.
Anyway: “reset” changes the ref to which the HEAD branch points, and depending on options can also update the index and working tree to match as well. “Revert” creates a commit that is the reverse of an earlier commit. Restore rolls back uncommitted changes to a file.
This isn’t hard?