These two terms might sound similar, but they actually mean different things. For something to be considered waterproof, it must have enough resistance to water to stay dry even in driving rain (or moving water).
The standards of testing differ between manufacturers, but any brand that says their product is waterproof can back up its claims easily.
Both of these are breathable though, so you do not need to worry too much about sweat. Waterproof fabrics will prevent the rain from getting to your skin, and also move sweat from your skin to the outside.
They are usually good if you are heading out on aerobic activities or hikes since you do not want to get drenched in sweat as you do them.
On the other hand, water-resistant items can handle light rain for short periods, but they will not hold up beyond a certain point.