Every trade occurs between two parties: the maker, whose order exists on the order book prior to the trade, and the taker, who places the order that matches (or “takes”) the maker’s order. Makers are so named because their orders make the liquidity in a market. Takers are the ones who remove this liquidity by matching maker’s orders with their own. Every trade will have one maker and one taker.
The maker-taker model encourages market liquidity by rewarding the makers of that liquidity with a fee discount. It also results in a tighter market spread due to the increased incentive for makers to outbid each other. The higher fee that the taker pays is usually offset by the better price discovery