The Adobe Flash Player is a widely distributed multimedia and application player created and distributed by Macromedia (a division of Adobe Systems). Flash Player runs SWF files that can be created by the Adobe Flash authoring tool, by Adobe Flex or by a number of other Macromedia and third party tools.

Adobe Flash, or simply Flash, refers to both a multimedia authoring program and the Adobe Flash Player, written and distributed by Adobe, that uses vector and raster graphics, a native scripting language called ActionScript and bidirectional streaming of video and audio. Strictly speaking, Adobe Flash is the authoring environment and Flash Player is the virtual machine used to run the Flash files, but in colloquial language these have become mixed: "Flash" can mean either the authoring environment, the player, or the application files.

Flash Player has support for an embedded scripting language called ActionScript (AS), which is based on ECMAScript. Since its inception ActionScript has matured from a script syntax without variables to one that supports object-oriented code, and may now be compared in capability to JavaScript (another ECMAScript-based scripting language).

The Flash Player was originally designed to display 2-dimensional vector animation, but has since become suitable for creating rich Internet applications and streaming video and audio. It uses vector graphics to minimize file size and create files that save bandwidth and loading time. Flash is a common format for games, animations, and GUIs embedded into web pages.

The Flash Player is built into some browsers and is available as a plugin for recent versions of other browsers (such as Mozilla Firefox, Opera, Safari and Microsoft Internet Explorer) on selected platforms. Each version of the plugin is completely backwards-compatible.