Betting is considered a part of gambling. But the two terms are a little different. In gambling, the wager or the bet is placed on something random and without any basis of the result. In betting, the stakes or the bet is placed on the happening of a contingency. The point is that in betting we have an idea of what the results might be.
Gambling is purely random and based on luck. There is no trick where the player can know the outcome of any game. Betting is about prediction. People who bet place their wagers on an event that is likely to happen based on events present.