Sports Bet Com Do All Sports Betting Sites Take Money Out Of What You Earn From Each Winning Bet?

Do all sports betting sites take money out of what you earn from each winning bet? - sports bet com

I'm trying a new location paris sport, but I do not understand why you do not receive the full amount you bet. As if I bet $ 10 on a game get everything in order, as only 4 U.S. dollars to win the bet. Why is it 10?