The CEG technology creates a unique, encrypted copy of the game's executable files for the given user which allows them to install it multiple times and on multiple devices, and make backup copies of their software.Once the software is downloaded and installed, the user must then authenticate through Steam to de-encrypt the executable files to play the game.In May 2012, the service added the ability for users to manage their game libraries from remote clients, including computers and mobile devices; users can instruct Steam to download and install games they own through this service if their Steam client is currently active and running.
The Steam platform is the largest digital distribution platform for PC gaming, estimated in 2013 to have 75% of the market space.
In 2015, users purchasing titles through Steam or through Steam keys from third-party vendors totaled roughly $3.5 billion, representing 15% of the global PC game sales for the year, based on estimations made by the tracking website Steam Spy.
80,000–300,000 gamers tested the system when it was in its beta period.
Around that time, Valve began negotiating contracts with several publishers and independent developers to release their products, including Rag Doll Kung Fu and Darwinia, on Steam.
Steam also offers a framework for selling and distributing downloadable content (DLC) for games.