There are a variety of other specific rules that can apply depending on the type of pool being played, but these are the basics. The first player to sink all their balls (or the player with the lowest score if the game is unfinished) is the winner. Players are also allowed to sink the cue ball, which can be used to strike other balls.
The official rules of pool are quite complex, but can be generally summed up as follows: each player is assigned a certain number of balls, which they must sink in specific order.