Multiplayer games : I never even look up if there are cheats for that game, and even if there were, I would never use them.
And so far I didn't play any MP game that has walkthroughs, so I never used them.
Single player games : I only and I do mean only use cheats once I've finished the game myself. When I do, I look up for some fun cheats mostly because I've done everything in the game, but I never use them before I finished the game, and got all the collectables/unlockables...
And I only use walkthroughs when I'm really stuck somewhere and spent several hours trying to figure out what to do, in vain, which rarely happens.
Tessh, Cheats are cheat codes, some sort of hacks maybe, to give you special abilities in a game, such as infinite health, unlock all unlockables automatically, infinite ammo...
Walkthroughs are guides to help you see how you go through the game from the beginning to the end.