CS:GO has become free to play for all Steam-users. Additionally you can get a Prime-status to unlock more features. Players can purchase Prime for 15 dollars. Those who are willing to put some effort can get it for free. In this case you have to achieve 21st in-game level and verify your phone number. Prime status gives you an opportunity to play with other players who have Prime. Also you will get your own inventory and be eligible to receive drops and rewards. Players who purchased CS:GO before December 7, 2018 automatically received their Prime status. Also they will get a unique golden medal after logging into the game.