All valves will allow flow or block the flow. However, different types are optimized for different applications.
-gate valves should be full open or full closed. They should not be used to throttle flow. Also, they are know to allow at least a few drips to flow by in the closed position when used as the main shut-off in a residence.
-globe valves usually have a rubber washer and seat for complete shut off; the rubber needs frequent replacement. Also, the passage through a globe valve is small ( and turbulent) .
-ball valves can be full port, and ball seats are very reliable and long lasting. Ball valves are also full open/full closed. Not for flow control.
-hose bibb defines the connections: one end connects to house pipe but the other end has hose threads. Also, the outlet is angled for ease of hose connection. Sillcock just another type of hose bibb.
This is just a brief discussion of the vast topic "valves".