A seizure is muscle twitches and spasms associated with multiple neuron disruptions in the brain. 

The two types of seizure are a generalized seizure and a partial seizure. Generalized seizure are everywhere in the brain at once, while a partial seizure begins in one location of the brain.

A seizure consists of three stages. The aura is the start of seizure and can be broken down into a simple partial seizure (aura is the only part of the seizure experienced), a complex partial seizure (seizure affects consciousness), or a generalized seizure (seizure spreads to the rest of the brain). The ictus is the physical seizure. The postictal are aftereffects associated with the seizure.

A seizure is a single occurrence while epilepsy is two or more unprovoked seizures.