You can place bets as singles ("Single bets") or combination bets.
Single bets involve the outcome of only one game. Combination bets involve the outcome of more than one game.
Combination bets are shown on the betting slip as "multiple." The maximum number of different games in combination bets is 30.
In addition to these, there is also a system bet option, which allows you to place a series of single and combination bets at once.
Once you have placed and confirmed your bets, they are valid and cannot be changed or canceled. Some bets have a Cashout feature, which allows you to cash out your bet for a certain amount before the game is decided.
You can find information about your previous and open bets here: https://happycasino.com/en/sports?page=betHistory