The black ball changes its job
Snooker is about scoring points with reds and colours. In eight-ball pool, you clear your group, then legally pot the 8-ball to win.
Both use a cue and pockets, but the same-looking shot can mean something quite different. Pool is a family of games; here we are comparing standard snooker with WPA eight-ball.
Count before the break
Standard snooker starts with 22 balls: 15 reds, six colours and the white cue ball. The WPBSA rulebook lists the set.
WPA eight-ball uses 16 balls: 15 numbered balls plus the cue ball. Your group is numbers 1–7 or 9–15. The black 8-ball waits until your group is cleared, under the WPA rules.
Seven points or the winning shot?
In snooker, a red is worth one point and the black is worth seven. Pot a red followed by a black legally and you score eight points.
While reds remain, a potted colour goes back on its spot. The black can therefore help you score repeatedly. In eight-ball, its number identifies the ball you must finish with; it is not worth eight points.
The table gives you another clue
A full-size snooker playing surface is about 3.57 metres long. The WPA’s nine-foot pool specification has a playing surface 2.54 metres long. Those are playing areas, not outside measurements; home tables can vary.
Another sport with its own scoring language? Try love, deuce and advantage in tennis.