Random access 25612 225125457 2008-07-12T00:29:59Z Thijs!bot 1392310 robot Adding: [[hu:Véletlen elérés]] [[Image:Random vs sequential access.svg|thumb|right|Random access compared to [[sequential access]].]] In [[computer science]], '''random access''' (sometimes called '''direct access''') is the ability to access an arbitrary element of a [[sequence (mathematics)|sequence]] in equal time. The opposite is [[sequential access]], where a remote element takes longer time to access. A typical illustration of this distinction is to compare an ancient [[scroll (parchment)|scroll]] (sequential; all material prior to the data needed must be unrolled) and the [[book]] (random: can be immediately flipped open to any random [[page]]. A more modern example is a cassette tape (sequential—you have to fast-forward through earlier songs to get to later ones) and a compact disc (random access—you can jump right to the track you want). The term [[random access memory]] (RAM), however, is used for semiconductor chip memory circuits used in computers. (The term was also used to describe [[ferrite-core memory]] in early computers). In [[data structure]]s, random access implies the ability to access the ''N''th entry in a list of numbers in constant time. Very few data structures can guarantee this, other than [[array]]s (and related structures like [[dynamic array]]s). Random access is critical to many algorithms such as [[quicksort]] and [[binary search]]. Other data structures, such as [[linked list]]s, sacrifice random access to make for efficient inserts, deletes, or searches. [[Category:Computer data]] [[de:Wahlfreier Zugriff]] [[es:Acceso aleatorio]] [[fr:Accès direct]] [[he:גישה ישירה]] [[hu:Véletlen elérés]] [[ja:ランダムアクセス]] [[pt:Acesso aleatório]] [[zh:隨機存取]]