What is a touch attack?

[FrodoOf9Fingers]

This may see to be a very dumb question, but what is a touch attack, specifically in reference to Deadly Aim?

Deadly Aim wrote:

You can choose to take a –1 penalty on all ranged attack rolls to gain a +2 bonus on all ranged damage rolls. When your base attack bonus reaches +4, and every +4 thereafter, the penalty increases by –1 and the bonus to damage increases by +2. You must choose to use this feat before making an attack roll and its effects last until your next turn. The bonus damage does not apply to touch attacks or effects that do not deal hit point damage.

So, obviously no touch spells. How about splash weapons, which roll ranged touch attacks? Or the Gunslinger's ability to target touch AC?

[Chess Pwn]

If it says touch, it's a touch attack. Guns have something that lets them use deadly aim with them even though they are touch attacks.

[FrodoOf9Fingers]

Ah, I didn't see that, thank you so much, that clears up a lot.