Hacking is a smart way to enjoy pretty much any game.
Hacks are different than Cheats because hacks modify the game in a way that it wasn't meant to be played.
Hacks usually require reverse engineering of the game's engine, which is a time taking process but can result in a much more polished and quality hack.
Types of Hacks
- Allowing the game to run on unsupported hardware
- Forcing the game to do something it wasn't meant to do
- Gaining an advantage over NPCs or Players
- Unlocking hidden content (Read: http://gta.wikia.com/wiki/Hot_Coffee_Modification, adult-only content that was unveiled by hackers and modified to run resulting in huge legal trouble for Rockstar)