[1]
>A [DFN@en[prototype]] is an [[object]] used to implement structure, state, and behaviour inheritance in [[ECMAScript]].
When a [[constructor]] creates an [[object]], that [[object]] implicitly references the [[constructor]]'s associated
[[prototype]] for the purpose of resolving [[property]] references. The [[constructor]]'s associated [[prototype]]
can be referenced by the [[program]] [[expression]] [CODE(JS)@en[[[constructor]].[[prototype]]]], and [[properties]]
added to an [[object]]'s [[prototype]] are shared, through [[inheritance]], by all [[objects]] sharing the [[prototype]].

;; [CITE[ECMAScript Language Specification (HTML version)]] ([TIME[2009-04-03 04:43:48 +09:00]] 版) <http://bclary.com/2004/11/07/#a-4.3.5>

* 関連

[3] [[プロトタイプ]]を用いる[[オブジェクト指向]]を特に[[プロトタイプ型]]と呼んで[[クラス型オブジェクト指向]]と区別します。

[2] [[JavaScript]] [[ライブラリー]]である [[Prototype.js]] は [[JavaScript]] [[言語]]の概念である「[[プロトタイプ]]」
と直接の関係はありません。