What is 10-ball?
10-ball meaning the pool game played with only the first ten balls (1-10), racked in a triangle pattern with the 10-ball in the center. The lowest numbered ball must always be hit first, and all shots must be called (i.e., slop doesn’t count). The person who pockets the 10-ball wins the game.
reference: billiards.colostate.edu: Glossary of Pool and Billiards Terms and Phrases