Roulette - Types of bets

Inside Bets

• Straight: a single number. The chip is placed entirely on the middle of a number square.
  
• Split: a bet on two adjoining numbers, either on the vertical or horizontal (as in 14-17 or 8-9). The chip is placed on the line between these numbers.
  
• Street: a bet on three numbers on a single horizontal line. The chip is placed on the edge of line of a number at the end of the line (either the left or the right, depending on the layout).
  
• Corner (or square): a bet on four numbers in a square layout (as in 11-12-14-15). The chip is placed at the horizontal and vertical intersection of the lines around the numbers.
  
• Sixline (or 'sixaine'): a bet on two adjoining streets, with the chip placed at the corresponding intersection, as if in between where two street bets would be placed.

Outside Bets

• Even Money Bets: a bet on 18 numbers. This is placed in the a box representing the attribute (black/red/low/high/even/odd) that you wish to bet on.
  
• Group Bets: a bet on the first, second, or third group of twelve numbers.
  
• Column: a bet on all 12 numbers on any of the three vertical lines (such as 1-4-7-10 on down to 34). The chip is placed on the space below the final number in this string.

From Wikipedia's