Steam includes a digital storefront called the Steam Store, through which users can purchase computer games digitally. Once purchased, software is permanently attached to the user's Steam account. Content is delivered using a proprietary file transfer protocol from an international network of servers. While logged in, games can be downloaded to any computer that has the Steam client installed. Steam includes a server browser for users to search, filter, bookmark, and join Internet and LAN servers for games that integrate with it. It can be accessed from the desktop or from a games menu system, and queries friends to show a list of servers to which a user's contacts are connected. Currently accounts cannot be merged or deleted by their creators.

Once patches for a user's installed software have been uploaded to Steam, they are applied the next time the user logs in or launches a game. Once a patch has been applied, it cannot be removed unless a patch is released which reverses the previous one. Individual games can be set to only update when requested by the user. Steam requires that games be fully patched before they can be played, however.

Valve Anti-Cheat (VAC), Valve's proprietary anti-cheat system, is available for online game servers to use. VAC-secured servers automatically detect users who are using cheats.