What are single, combination and system bets?

A single betting is one bet on one particular game or event.
 
A combination betting is a bet combining several bets. All bets must be won before the bet can be paid out. The combined odds posted are multiplied by each other and subsequently by the player’s wagers. The result is then the potential profit of that combination bet. Up to twelve matches or odds posted may be combined.
 
A system betting is a bet, which combines several odds posted. Depending on the type of combination, a potential profit will be granted. Assigning a ‘banker’ means that that particular odd posted will be included in all the combinations. In other words: you're pretty sure you will win that particular bet and therefore you want to include it in all combinations that are part of the system betting.