Swapping

Swapping is the act of exchanging one thing for another, or the process of temporarily relocating data. In computing, the term has two prominent meanings. Memory swapping moves data between RAM and a dedicated swap space on storage to extend usable memory. When the system is short on physical memory, pages are swapped out to disk and swapped back in as needed. Swap space may be a file or a dedicated partition; overuse can slow the system (thrashing). The swappiness parameter influences how aggressively the system uses swap. In programming, swap also refers to exchanging the values of two variables, typically via a temporary variable or an XOR-based method.

In finance, a swap is a derivative contract in which two parties exchange cash flows or liabilities. The most common is the interest rate swap, in which fixed payments are swapped for floating payments on a notional amount. Currency swaps exchange principal and interest in different currencies. Other forms include commodity or credit default swaps. Swaps are used for hedging interest-rate or currency risk, adjusting funding costs, or speculative positioning. Valuation centers on discounted cash flows, with attention to counterparty risk and collateral, especially under modern clearing and margin rules.

In everyday usage, swapping also denotes general exchanges of goods, services, or properties—such as time-based exchanges, home or car swapping, or bartering—as an alternative to direct purchase.