What does covering the spread mean?

The scoreboard and the spread are two different things.

A spread adds or subtracts points from the selected team’s final score for grading. It does not change the actual game score.

If your team loses 24–20 and your selection is +6.5, its adjusted score is 26.5. That covers against 24. If the selection is −6.5, the team must win by more than 6.5 points.

A whole-number spread can push when the adjusted scores tie. Overtime, shortened games and other exceptions depend on the sportsbook’s rules. The sportsbook’s settlement remains authoritative.