Short answers, pulled from the story.
Steam launched in September 2003 to solve the problem of players disconnecting from servers while installing patches for Valve's multiplayer games. The service provided an automatic system that kept users connected and updated without requiring manual intervention.
Valve received rejection from all three companies including Microsoft Yahoo and RealNetworks after approaching them to build the client. This failure led Valve to begin its own development in 2002 under the working names Grid and Gazelle.
Valve takes a flat 30% revenue share on all direct sales and microtransactions until October 2018 when they adjusted the cut to 25% for games earning over one million dollars. Further reductions to 20% apply once revenue exceeds five million dollars.
Valve responded by launching Steam Guard in March 2011 to protect against account hijacking via phishing schemes using Intel Core processor security features. Two-factor authentication was later expanded to include mobile applications known as Steam Guard Mobile Authenticator.
The Steam Deck handheld console launched in 2022 designed specifically for running Steam games with support for Windows Linux and macOS clients. Native Apple silicon support was added after Intel-based Macs were discontinued in late 2025 while Windows and Linux compatibility remain active.