The word box has several common meanings:

1. A container with flat sides and usually a lid, used for storing or carrying things. You might keep your baseball cards in a shoebox, pack a moving box with books, or receive a birthday present wrapped in a decorated box. Boxes come in countless sizes and materials: cardboard boxes for shipping, wooden boxes for tools, metal boxes for valuables. When you box something up, you're putting it into a box for storage or transport.
2. A sport where two people wearing padded gloves fight according to strict rules in a square ring. Professional boxers train for years to master punching techniques, footwork, and defense. A boxer fights in specific weight classes to ensure fair matches. The sport is also called boxing, and despite the name, the ring where boxers fight is actually square.
3. A small enclosed area or compartment. At a theater, a box is a private seating area. On a form, you fill in boxes with your information. A jury sits in the jury box during a trial. Baseball players wait in the batter's box before their turn to hit.
4. To fight with your fists, or to pack things into containers. You might box your old toys to donate them, or learn to box at a gym.