description means that there is over-growing of the lower edges of your spine bones which is minor and not a cause to worry.
DISCS are soft cushion like structures between your spinal bones to support them and help movement. disc bulging means that this cushion has become loose and stretched to bulge out from the normal gap between the bones. so now it is entering the space occupied by the nerves which supply your legs. resulting in compression of these nerves and hence the pain.
hope this is helpful