Schooling is a very belittling term used to describe what weak-loose poker players do as a defense mechanism. (Sheep flock; fish school.) If a pot is fairly small on the turn in a game of Holdem, and the player with the best hand bets, any single player with only a gut-shot draw will be making a significant mistake by calling. But now suppose several other people call too, with other gut-shot draws.
Because these other players are playing bad also, now the pot has grown to the point where the gut-shot draws are getting better pot odds on their calls. These bad calls “school” together and miraculously become not-so-bad calls!
Schooling is a part of the reason many weathered players complain that they are unable to beat loose games. Everybody going to the river, sucking out every possible draw, how can a sensible player make a hand “hold up” and beat such a game? Well, it is not all that hard really. A winning player merely wins money differently (and with a higher variance) in these games.
Schooling games give good players two main ways to win: either by playing the best made hand or the best draw. There is more money to be made overall, but you have to make sure your game adapts to get the profit from both of these ways.
You beat a schooling game the same way you beat any other game — play smart, appropriate poker.

