You may call it a contest where those who predict correctly wins the prizes. The difference between this and gambling is that here you are just participating in prediction without investing your own money while in gambling you would invest your own money in order to participate in prediction.
Anyways I do agree that most people will consider these two scenarios as same and will treat both of them as gambling.
The truth for this is that we can refered to them all as gambling since what most of us understand as gambling is the involvement of a staked amount and since e in both playing inhouse games or making a prediction involve financial involvmennt with the expectations to win make them all gambling.
So at this point, we cant separate the two from each other and we must align ourselves with that u understanding.