load

Load is a term used across disciplines to denote the external influence acting on a system or the demand placed on a resource. In physics and engineering, a load is any force or combination of forces acting on an object, which can cause deformation, stress, or energy transfer.

In structural and civil engineering, loads are categorized to aid design. Dead loads are the permanent weights of the structure and fixed components. Live loads are variable, such as occupants, furniture, and movable equipment. Environmental loads include wind, snow, rain, and seismic events. Designers apply load combinations and safety factors to ensure strength and stability under anticipated conditions.

In electrical engineering, a load is a device or portion of a circuit that consumes electrical power. Loads can be resistive, inductive, or nonlinear. Power in a load is determined by voltage and current, and for alternating current, by apparent power and power factor in addition to real power.

In computing and information systems, load refers to the amount of work placed on processors, memory, storage, or networks. System load averages or queue lengths measure how busy a system is, while load balancing distributes work across resources to optimize performance. In software testing, load testing assesses how a system behaves under high demand.

In cognitive psychology, cognitive load describes the mental effort required to perform a task, with strategies such as chunking and interface simplification used to reduce unnecessary load.

Across fields, the central idea is a demand on a component or resource that must be designed, controlled, or managed to maintain function and safety.