The objective of the game is to predict the number on which the ball will land (black or red, odd or even number, dozen etc).
Either you play in an online or in a real casino, the rules are the same by 99.9%. The rest 0.01% is about the way that we place the bet.
At an online casino there is specific time during which you can place a bet (20 seconds). If that time passes, you will have to wait till the next round.
At real casino, the croupier calls the shots. The bets stop as soon as the ball touches the wheel.
The croupier of course will let you know about the end of bets’ round, but you will also have to move fast. In addition, it’s the croupier’s duty to pay the bets and remove the lost ones from the table.
You can play online roulette here