In my opinion they are both the same, If you bet you are gambling even if you are not betting real money as long as you are betting you are gambling something. I really don't know any difference between the two but the is only my opinion. correct me if i am wrong.
Yes the only difference of these two are the spelling. In sum up, the meaning of gambling and betting is the same. Betting is an act of gambling so in other words there's no difference about it. The only thing that you can see is that gambling has a lot of games to bet. And gambling is a way preferred word by most of the people.