Bookmaker market means betting with the bookmaker and betting on the odds they offer. When you bet on a traditional bookmaker you are betting against Khelaghor rather than against other Khelaghor’s customers. Therefore it is Khelaghor who sets the prices and carries the risk.
A betting exchange, on the other hand, offers more competitive odds due to its nature as a peer-to-peer platform and the market is driven by supply and demand. It matches bets from backers and layers, you could be betting against one person or several in a betting exchange. The odds are generally higher for the betting exchange than for the same selections in traditional bookmakers, but unlike the traditional bookmaker, when you place a bet on a betting exchange you will need to pay commission on your net winnings on each market.