What does this all mean. The central spinal canal is widely patent mild broad-based disc buldge at L5-S1 partial left L5 hemilaminectomy defect mi?

Disk disease of back. The central (spinal) canal is open. There is a disk bulge at L5-S1 which may or may not cause any problems. There is part of the L5 vertebrae that is not there. Probably congenital and not an major issue.