capacity

Capacity is the maximum amount or level that something can contain, produce, or accommodate. It is a property of a system, object, or process that constrains its performance or storage potential. The concept appears in physical, technical, and organizational contexts and is often contrasted with demand, utilization, or actual output.

In physical terms, capacity describes how much a container can hold or the maximum volume a space can accommodate. Units may include liters, gallons, cubic meters, or bushels, depending on domain. For example, a tank with a capacity of 5,000 liters can hold up to that volume when filled to its brim. Container capacity also applies to packaging, shipping, and infrastructure such as reservoirs or silos.

In electrical engineering, capacitance is a form of capacity that measures a component's ability to store electrical energy, measured in farads. In computing and information technology, capacity often refers to data storage capacity, such as bytes, megabytes, or bytes per second for throughput. Storage devices and networks are described by their capacity and achievable data rates, and capacity planning must account for growth and reliability.

In operations management, capacity refers to the maximum output a process or facility can sustain over a period. Capacity planning involves forecasting demand, determining resources, and sizing systems to balance service levels, costs, and utilization. Terms like nominal design capacity, effective capacity, and bottlenecks are used to describe different aspects of how capacity is constrained and exploited.