The game currency is the currency that a game is played in. Each game has its own specific currency. The amount of money either on the table or in the machine will be displayed in the game currency, and all buy-ins and payouts are processed using the game currency rather than your account currency. It is possible, that the game currency is the same as your account currency, or different in which case you will be able to convert your money into the game currency.
Every game is different, and in a lot of games released today you can find different in-game paying methods, an alternative to real money that are used in game for paying for different services or tools that will ease the game level. You can get money for passing different missions in a specific game, or you can get those in-game money by paying real money for them. Or the easiest way is downloading some money cheats from https://lavicheats.com/overwatch-hacks-aimbot/. Here you can find cheat codes for the most popular games available on the market, hope you won’t be disappointed.