Steam, created a few years ago, is a platform which once served as a multiplayer system called the WON. After many years, Steam has been changed and significantly improved. Currently, the platform offers the opportunity to play games, buy games, have an account etc. The platform also offers social functions and the ability to store data.
Random Key, in turn, is an interesting proposition for people who like surprises. We buy a random key to download the game for a small amount of money. Premium Key offers bigger chance of winning cool, new games.