There are all sorts of different socks for people to use such as athletic, tube, diabetic, and compression socks. Of these mentioned, the last two are made specifically for use by individuals with health problems that deal with issues related to the feet. Diabetics needs socks that do not constrict the legs as their veins are dealing with diabetic issues. The socks of the compression variety are the opposite as they are made to constrict the leg in such a way as to improve circulation in the lower leg and feet.
Compression socks are created with graduating pressure that is tightest at the ankles and loosens up as it moves up the leg. There are many issues that can arise with poor circulation such as the pooling of blood in the feet. Most people need to walk to get somewhere and so their blood will drop to their feet as gravity works. Compression socks will help to fight gravity and help the veins move the blood up the legs.