In roulette, winning odds vary based on the type of bet and the game variant, such as European or American roulette. European roulette, with a single zero, offers better odds compared to American roulette, which has both a single and a double zero, increasing the house edge. Bets are categorized as inside or outside; inside bets yield higher payouts but lower winning odds (about 2.63% in European roulette), while outside bets offer higher winning odds (around 48.6%) but lower payouts.