Sport and a Game
It looks like the history claims it is both a game AND a sport:
In the United States, though the original "pool" game was played on a pocketless carom billiards table, the term later stuck to all new games of pocket billiards as the sport gained in popularity,[citation needed] and so outside the cue sports industry, which has long favored the more formal term pocket billiards, pool has remained the common name for the sport.
There are hundreds of pool games. Some of the more well known include eight-ball, nine-ball, ten-ball, straight pool, and one-pocket.
It looks like the history claims it is both a game AND a sport:
In the United States, though the original "pool" game was played on a pocketless carom billiards table, the term later stuck to all new games of pocket billiards as the sport gained in popularity,[citation needed] and so outside the cue sports industry, which has long favored the more formal term pocket billiards, pool has remained the common name for the sport.
There are hundreds of pool games. Some of the more well known include eight-ball, nine-ball, ten-ball, straight pool, and one-pocket.