Today, multiplayer gaming is easy. You hop onto a game, press "play online," and in moments, you're in an arena playing with people all over the world. Sometimes the game matches players with the same skill level or gamers who live closer to one another for better latency and ping. Some games have options for a competitive gaming mode or something casual. Overall, playing online with other people is a pretty simple process.
That accessibility comes from the pains of the past. Formerly, games might have required a specific IP address for a server, requiring coordination with your friends to join the same server. That address came from somewhere on the internet like a message board.
In comparison to what we have today, it was cumbersome and not exactly user friendly. In the mid-90s an app called GameSpy hit the scene which made browsing for servers and connecting with players a far more intuitive process. It was a game-changer.