Yes, there are differences between those things.

Poaching is cooking in hot liquid, but the liquid is not boiling or even simmering, so it is a lower temp than both.

Saute generally means you're using a small amount of oil/fat and stirring/tossing the food to spread the oil/fat around on everything while cooking everything. Pan frying generally means you're cooking a larger piece of something and not tossing it around.