Some people like finding ways to bend the rules without outright breaking them. Thus the word "exploit": You're exploiting the way the game works in a way that wasn't intended.
Exploits and cheats are the same thing. You're getting around intended game rules one way or the other. It's only the type of method and deniability that varies... but why bother lying to yourself in a single player game? If you're doing it on purpose, you're cheating.
I disagree completely. A cheat to me is something like "hit these buttons and get infinite ammo, etc".
An exploit *still* requires some skill, sometimes. I mean okay, the dupe exploit in Oblivion takes little to no skill, at all.
The tougher an exploit is then the people feel that it's *okay* to use since technically, they having to earn it. Personally, I'd have just modded it in but each person is different.
The primary difference between an exploit and a cheat is this:
An exploit can typically be used through in-game methods.
A cheat typically uses outside-the-game methods.
However, both of them bypass how the game is intended to work by the person(s) who made the rules for the game.
So it is only a technical difference, and primarily changes how people may or may not
feel about the legitimacy of the method.
However, no matter how strongly people
feel about getting around the intended rules, it's still cheating. It doesn't matter if you press A B A B Up Down or install an outside program to press it for you, if you're circumventing the intended rules, it's a cheat. Pleading ignorance is not a defense, ie "oh well you can get infinite adamantine by doing a certain bizarre series of steps which make absolutely no sense in normal terms and are almost certainly bugs, so surely Toady wanted people to be able to get infinite adamantine! That means it's supposed to be this way! I didn't use a hack!" Nope. Cheat.
Edit: Of course it's a single player game, so it's not really a big deal... if you're cheating anyone, it's yourself. However, if it were multiplayer and someone were using program bugs to unfairly kill you and spoil the intended flow and balance of the game, you might reconsider your thoughts on what's cheating and what is not.