Now hold just one end and let the other drop. This what an automotive spring does if it doesn't have a shock absorber attached to it. Struts are simply shock absorbers used as major structural members. For struts, the shock absorber is placed inside the coil spring. In addition to saving space, it often costs less.
Many cars use a strut design.
Shocks and struts help control how fast the suspension is allowed to move, which is important for keeping the tires in contact with the road. Obviously, there is a lot more weight in the upper part of the car than unsprung weight in the lower part of the car. We realize this is a simplistic view of a complex system. In our next chapter in the series, we'll get a little more technical and a little more specific, looking at particular spring and suspension setups, and the advantages and disadvantages of each. Until then, keep your eye on the road, and watch out for those potholes.