What is the passive voice and how is it used in French?

In the most simple terms possible, the passive is a voice that describes all events in the indicative tenses but where the object and the subject simply switch. This means that where in an indicative sentence the subject does the verb to the object - in the passive, the object is being done by the subject and so it appears first in the sentence. For example - The man eats his lunch - goes to: the lunch was eaten by the manIn French: L'homme mange son déjeuner. = Le déjeuner est mangé par l'homme.