The passive voice is a grammatical construction (a "voice") in which the subject of a sentence or clause denotes the recipient of the action (the patient) rather than the performer (the agent).
In the English language, the English passive voice is formed with an auxiliary verb (usually be or get) plus a participle (usually the past participle) of a transitive verb.
For example, Caesar was stabbed by Brutus uses the passive voice. The subject denotes the person (Caesar) affected by the action of the verb. The counterpart to this in active voice is, Brutus stabbed Caesar, in which the subject denotes the doer, or agent, Brutus.