French Compound Past
Le Passé Composé is used in French to express actions which completed or finished in the past (as opposed to the imparfait which we use for habits or actions that were ongoing in the past).
The passé composé can be tricky for English speakers, as it looks a lot like the present perfect (e.g. I have done), but its meaning and usage is generally more like the English simple past (I did). It's used in day-to-day conversation whenever we talk about things that have happened.
We form Le Passé Composé using avoir or être (called the auxiliary verb) plus the past participle of the verb for the action itself.
Because the passé composé is always made up of two verbs, the auxiliary (avoir or être) and the action verb, it's known as a compound tense.
See also: French Passé and All French tenses