What is the meaning of "seizure" and "epilepsy"?

A seizure is a sudden, uncontrolled electrical disturbance in the brain that can cause changes in behavior, movements, feelings, and consciousness. Seizures range from brief staring spells called absence seizures to full-body convulsions called tonic-clonic seizures. Epilepsy is a chronic neurological disorder characterized by recurrent unprovoked seizures, from the Greek epilepsia meaning to seize upon. A single seizure does not constitute epilepsy. Diagnosis requires two or more unprovoked seizures occurring at least 24 hours apart.