There are a lot of words that are used in describing the different types of damage that can show up when the rubbery disc between segments of the spinal column are damaged either through injury or wear and tear. The old fashioned term "slipped disc" has no real meaning, but there is confusion between the terms "bulge", "protrusion", "herniation."
A disc herniation is a condition where the disc itself has been damaged to the point that it spreads beyond the boarder of the vertebral body over at least 50% of the circumference of the vertebral body. A herniation of a disc extends beyond the boarder of the vertebral body for less than 50% of the circumference of the disc. Bulges and herniations maybe be focal if they are localized or broad based if they extend broadly around the disc. A protrusion is a special kind of herniation that extends farther out from the disc itself. An extrusion is an even more extreme form of protrusion.
Finally, a free fragment is piece of disc material that has broken loose entirely from the disc material.
These terms are often used in the reports generated by radiologist when they read films generated after a Magnetic Residence Imaging Scan or "MRI."
Often times, Radiologist do not use the same definitions. One Radiologist might read a film as showing one thing, where another might find something else. That is why it is always better to let these films speak for themselves in your medical history and not to advise doctors that you suffer from any "herniation" or "disc bulge."