A bulging disk simply extends outside the space it should normally occupy. The bulge typically affects a large portion of the disk, so it may look a little like a hamburger that’s too big for its bun. Usually bulging is considered part of the normal aging process of the disk and is therefore common to see on MRIs.
A herniated disk, on the other hand, results when a the center of the intervertebral disk (the nucleus pulposus) protruding out through the tough outer layer of cartilage (called the annulus fibrosus). Herniated disks are also called ruptured disks.
Below CT of Disk Herniation of the L4-L5 intervertebral disk