Capacity is the ability to hold something, very similar to volume.

Capacity may also mean:

• Capacity in economics, how much a company or a government uses its potential output
• Capacitythe legal ability to do certain things, such as making a contract
• Capacity of a set, in mathematics, one way of measuring a set's size
• Battery capacity, a measure of a battery's ability to store electrical charge
• Carrying capacity, in biology, the ability of an environment to sustain populations
• Channel capacity, in communications
• Combining capacity, in chemistry, number of chemical bonds formed by the atoms of a given element
• Heat capacity, in physics, the measure of how materials store heat as they change temperature
• Nameplate capacity, in power plants, the general number of Megawatts technically available
• Seating capacity, how many people can fit into in a sports venue