Stemming from the establishment of high-speed trading in the late 1990s, maker-taker fees add liquidity to a market.
Makers
A maker is someone who places a buy or sell limit order that is not carried out immediately and thereby helps to "make the market" by adding liquidity. A "liquid asset" is one that can be easily sold, and "market liquidity" implies that assets can be easily bought and sold at fair prices.
Takers
A taker is someone who places an order that is immediately filled. Takers typically pay a higher fee than makers in any market, crypto or otherwise. See
crypto trading.