The "bases" in baseball refer to four specific locations on the baseball field that are key points in the game and must be touched by runners in turn to score points. The four base packs are:

1. First Base: The base that the batter runs to first after hitting the ball.
2. Second Base: A goal that is located between first and third base, and the runner continues from first base.
3. Third Base: A goal that is located between second base and home base, from which the runner continues to advance.
4. Home Plate: The base plate that the runner eventually needs to return to, and where the batter begins to hit the ball. When a runner successfully touches home plate, the team scores one point.

In baseball, a batter hits the ball and becomes a runner and must touch first base, second base, third base in order, and finally return to home base to score. The goal of the defense is to stop the runner from advancing or knock him out by various means (e.g., catches, blocks, etc.). The distance between the bales is fixed, usually 90 feet (about 27.43 meters).