Screw-valve style hose taps use a screw valve mechanism (a handle or wheel that turns, moving its stem up and down the valve shaft to turn the water on and off), and are the most popular type of outdoor tap used by homeowners. However, because of the screw valve design, they tend to wear out frequently and can be difficult to turn after long periods of disuse.
Ball-valve hose taps use a rotational-motion handle (usually a 90-degree lever or quarter-turn wheel style) to turn water on and off easy and quickly. Due to this simple valve mechanism, the ball valve style tap is durable and easy to use, even if left for long periods without being used. However, it doesn't allow for mid-range water flow adjustment.
No-kink hose taps normally use a screw valve type of mechanism. The outlets of these taps tip down at a 45-degree angle, assuring that water hoses don't crimp and effect overall water pressure.
Loose-key, handle-style taps have a handle that you can remove when not in use to control water use, reduce water waste and prevent unauthorized water usage.
Bent-nose hose taps are screw-style valves attached to vertical pipes that have outlets slanted down at a 45-degree angle to avoid hose crimping. These taps are generally placed in garden and lawn areas as a stand-alone water source for hose or sprinkler hookups.
Freeze-free hose taps have a valve mechanism specially designed with a packing that prevents water from leaking past the stem shaft and the tap from freezing up during cold winter months.
Basin-style taps normally use a screw valve mechanism, but don't have threads at the tap outlet. This makes this style good for outdoor sinks and other areas where attaching a water hose is not necessary.