There are many different types of coffeemakers using a number of different brewing principles. With most common devices, coffee grounds are placed in a paper or metal filter inside a funnel. The filter or funnel is set over a glass or ceramic coffee pot. Cold water is poured into a separate chamber, which is then heated up to the boiling point, and directed into the funnel.
A coffee maker can be an electrical appliance in which case it will automate most of the brewing steps. Or it can be a simple manual brewing device, such a pour over, or a dripper, used with hand drip technique.