Final answer:
Meningitis is an infection or inflammation of the membranes covering the brain or spinal cord. It can be caused by bacteria or viruses and can have serious consequences if left untreated.
Step-by-step explanation:
Meningitis is any infection or inflammation of the membranes covering the brain or spinal cord, called the meninges. It can be caused by bacteria or viruses. Bacterial meningitis tends to be more severe and can lead to serious long-term consequences or even death if not treated quickly. Viral meningitis often clears up on its own after a few days.