Cuse, WAR is wins above replacement which is a counting stat. "Replacement" is meant to approximate an average triple-A player. The logic is that if a major leaguer got hurt and couldn't play, you assume that the team would call up and replace him with an average triple-A player, or in other words, a replacement level player. So for Belanger, over the course of his career, the Orioles won about 41 more games by virtue of playing him and not Joe Schmoe Rochester Red Wing. It's an approximation but that's what that means.
For a single season, 4+ WAR is usually all star territory and 7+ is usually flirting with MVP. Usually around 50 WAR is where the Hall of Fame conversation starts. But the whole thing is an approximation and not the end-all be-all.