Other forms: passive voices
In grammar, the passive voice is what you use when a sentence's verb acts upon the subject. "The dog chased the cat" uses the active voice, but "The cat was chased by the dog" uses the passive voice.
When you use the active voice, your sentence's subject performs the action of the verb: "I threw the ball through your window." The passive voice is less direct and straightforward, with the subject being acted upon by the verb: "The ball was thrown through your window." There are many reasons to use the passive voice, but one of the most useful of these is when you don't want to be specific about who (or what) performed the action.