No matter what you call them, they all pretty much do the same thing: control the movement of the suspension. Your vehicle is held up by spring tension. If you didn't have struts, shocks, or dampers when you went over bumps, your vehicle would bounce all over the road. Dampers help prevent this from happening and are designed to keep your tires on the road.
When they go bad, they can not only cause this condition, but they can also make noise. An easy check to see if your dampers are bad is to bounce each corner of the vehicle. It should recover and come back to normal after about three bounces. If it doesn’t, it might be time to take a closer look at the dampers. What you’re looking for is oil leaks. If you see oil leaks on a strut or shock, it's bad and needs to be replaced.
The dampers use this oil in their operation; when it leaks out, the damper’s ability to do its job is compromised. There are also other parts of the strut that can cause noises. These are the upper strut mounts. Sometimes the strut is still good, but the upper mouth or bearing plate has a problem. If the bearing plate is a problem, you can often hear the noise when you turn the wheel left or right. I usually put my hand on the upper mount while I have a buddy turn the wheel. If I can feel the noise, I suspect the upper strut mounts or bearing plates are the problem. Here are a couple of videos concerning struts you may find useful.