Passive constructions are those in which a verb's action is performed on the subject, rather than the subject performing the action as in active (normal) constructions. The passive voice is the most common French passive construction, but there are a couple of others to watch out for as well.
Basic French Grammar
Agent | Subject | Verb | Voice
French Passive Voice
What is the passive voice?
How to form the passive voice
How and when to use the passive voice
Test on the French passive voice
Other French Passive Constructions
Even though the French infinitive translates as "to + verb," the French infinitive sometimes needs to be preceded by a preposition. This is the case with the passive infinitive, which is commonly used with indefinite and negative words, such as Il n'y a rien à manger - There's nothing to eat.
In the passive reflexive construction, a normally non-reflexive verb is used reflexively in order to express the passive nature of the action, as in Ça se voit - That's obvious.
The reflexive causative (se faire + infinitive) indicates something that happens to the subject, either per someone else's implied action or wish or unintentionally.