In my perspective, both are dependent on the luck.
Of the two betting is less risky because you can predict with the help of some criteria such as strength or weakness. But in gambling you must be dependent on luck.so betting is the safer of the two sides.
I believe both are different words with the same meaning. Gambling is just a term used for the overall activities of games were money something is risked hoping for better earning. Betting seems to describe a particular event were certain amount has been risked expecting big.