The vig (or juice) is the sportsbook's cut. At -110 on both sides, the implied chances add up to 104.8% instead of 100%; the extra is how the book profits no matter who wins. Removing it gives the fair, no-vig odds.
If another sportsbook offers a better price than the fair odds, that bet has positive expected value. That's why shopping across books matters: our board compares up to 11 sportsbooks on every bet and ranks each one by expected profit per $100 after the cut.
See today's bets ranked by expected profit