It has classics from Backgammon (and its multiplayer equivalent, Ludo) to Terraforming Mars and up to modern titles released this year. Many are totally free to play with just an account. Some are paywalled behind premium access, but you only need one person at the table with a premium subscription to start the game, and then everyone else can participate for free.
You can play in real time with people or turn-based across days at a dozen different virtual tables simultaneously (it notifies you, either by email or other settings, whenever it's your turn).
It handholds you through legal moves, so you can use the platform to learn new games. Some of my in-person board game purchases came from games I learned here online!
FTFY