swap

Swap is a term with multiple meanings that involve exchanging items or values. In common usage it denotes the act of trading one thing for another, and in technical contexts it refers to operations that move data, money, or obligations between parties or locations.

In finance, a swap is a derivative contract in which two parties agree to exchange streams of payments or other financial instruments over time. Common forms include interest rate swaps (exchanging fixed for floating rate payments) and currency swaps (exchanging principal and interest in different currencies). Swaps are used to hedge risk, obtain favorable financing terms, or speculate. Key terms include notional principal, payment intervals, and maturity.

In computing, swap refers to memory management and to the operation of exchanging values. Swap space on a hard disk or SSD is used by operating systems to extend available memory by moving inactive pages out of physical RAM and back when needed. A swap file or dedicated swap partition stores these pages; excessive swapping can degrade performance. The term also appears in programming as an algorithmic operation to exchange the values of two variables, often implemented with a temporary variable.

Beyond these contexts, the concept of swapping appears in various disciplines where two sides exchange resources, obligations, or states, illustrating a broad utility in modeling exchanges, risk management, and data handling.