A market maker is a market participant who buys or sells a large amount of a specific asset in order to provide liquidity to the market and to make the financial market function smoothly. Generally, institutional investors such as investment banks are market makers.
Most Crypto trading companies are market makers, and so are many banks. Market makers offer sells (supply) to buy orders from customers (we the retail traders) and buys (demand) to our selling. This can provide liquidity to the market, reduce transaction costs and facilitate trading.
We can buy and sell as much as we want, when we want, because marketmakers are always in the middle of trading. Crypto is said to be a non stop 24 hrs transaction, in reality it is made up of market makers intervening to provide insufficient liquidity.
Understanding the ideas of market makers is very important in understanding the Crypto market. Because, for us individual traders, it is the “opponent” itself.