Gambling and betting are related to each other. Since gambling are just games where people bets. So I don't think you're question isn't right.
But if you see most sites promote as gamble while some say bet, so some people are confused.
Actually gambling is a specific sort of betting where we bet on games and mostly gambling means betting on games where only luck can make you win, while betting means skills plays a factor too.
This is makes confused indeed
Maybe the means is gambling = spesificly to dice, slot, ect games. betting = sports betting, poker, blackjack, ect games.
Anyway both of them is can't be inseparable, because the term that has been attached to each other.
Well maybe i prefer to betting, according to my explanation, betting have more chance to win, because several factors can affect the result, not just luck only.