In casino language, coins are the units a slot machine uses to count stakes and wins. Early machines took real metal coins or tokens, which is where phrases such as “max coins” and “coin-in” come from. Most land-based venues have since swapped coins for ticket-in/ticket-out vouchers and player cards, which ends jammed hoppers and the cost of counting and moving heavy coin.
The idea survived the move to video slots. Many games still let players choose a coin value and a number of coins per line, so the total stake is coin value × coins per line × active paylines. Paytables are often quoted in coins rather than cash, which is why the same game can show different cash prizes at different bet levels.
Coins and multi-currency lobbies
When you integrate games, check whether each title reports bets in coins or in currency, and how its coin denominations map to every currency you accept. Consistent denominations make bet limits easier to configure and easier for players to understand. See casino games integration.