There are a lot of different valves that are made specifically for certain devices. A backwater valve is used for sanitary drainage. A ball check valve is used for liquid or gel mini pump dispenser spigots. Multiple check valves can be connected in a series. These are just to name a few.
A check valve is a two port valve. This means that it has two openings. One port valve for the fluid to come through and the second port valve so the fluid can come out. Check valves work automatically and are not controlled by a person.