PBW, PBMB, n., acronym, also Play by Web, play by Message Board refers to a game in which players play over the Internet, either through chat programs or Internet message boards.
Addendum: A fairly recent occurrence with the rise of the Internet, PBW games offer gamers with no groups a way to play their favorite games without having to travel long distances to try and find a group. The benefit to PBW games is (usually over message boards) the opportunity to play every day, but the games can usually get cut short as players bore or real life intrudes, much like a table-top game.