If the spread is set at +7, the underdog must either win the game outright or lose by fewer than seven points in order to cover. For the favorite to cover, they must win by more than seven points.
A +1.5 spread is commonly seen in baseball betting, the standard runline for MLB. This spread means the underdog must win outright or lose by exactly one run to cover the spread. Alternatively, a -1.5 spread means that the favorite must win by at least two runs. Many baseball games are decided by fewer than two runs.