Memoization
Memoization — Memoization is an optimization technique that caches the results of expensive function calls and returns the cached result when the same inputs occur again. Memoization is a form of caching that stores function results keyed by their arguments. It trades memory for speed. Ideal for pure functions with expensive computations, recursive algorithms (like Fibonacci), and repeated API calls. Implementations range from simple caches (`Map`-based) to sophisticated LRU caches with TTL. This term relates to the Function category of the reference. You will meet memoization in practice when working with APIs such as Function.prototype.call(), Function.prototype.apply(), Function.prototype.bind(), Function.prototype.toString(). Related terms: Closure, Hoisting, Event Loop, Prototype Chain, Temporal Dead Zone (TDZ), IIFE (Immediately Invoked Function Expression). Understanding memoization makes the rest of the JavaScript documentation noticeably easier to follow, because the concept recurs across methods, guides, and error messages. Look up more definitions in the JavaScript glossary.