Final answer:
Spina bifida is a malformation of the spinal cord before birth that occurs when the neural tube does not completely close. It has three types, each with varying levels of severity and symptoms.
Step-by-step explanation:
Spina bifida refers to a malformation of the spinal cord before birth. It is a birth defect caused when the neural tube does not completely close during development. The result is the emergence of meninges and neural tissue through the vertebral column. Spina bifida has three types: occulta, meningocele, and myelomeningocele, each with different levels of severity and neurological symptoms.