ACTIVE VOICE: the subject of the sentence performs the action of the verb.
PASSIVE VOICE: the subject is acted upon; the subject receives the action of the verb. This can often be identified with the phrase “by the…” but the passive voice can also be used without that phrase.
ex: A bus hit a tree. ACTIVE VOICE: The bus (subject) hit (verb).
ex: A tree was hit by the bus. PASSIVE VOICE: The tree is being acted upon/receives the verb (hit). Note the “by the…” phrase.