Steam is often a digital distribution platform put together by Valve Corporation offering digital rights management (DRM), multiplayer gaming and online community services. Steam provides the user with installation and automatic updating of games on multiple computers, and community features like friends lists and groups, cloud saving, and in-game voice and chat functionality. The program provides a freely available application programming interface (API) called Steamworks, which developers can use to integrate lots of Steam's functions inside their products, including networking, matchmaking, in-game achievements, micro-transactions, and support for user-created content through Steam Workshop.

Though initially developed for use on Microsoft Windows, versions for OS X and Linux os were later released. Applications whose main functions are chatting and shopping have also been released for iOS, Android and Windows Phone cellular phones. The Steam website also replicates most of the storefront and online community options that come with the stand-alone application.