What is the conditional perfect and when is it used?

The conditional perfect is a compound tense made up of: -the conditional form of avoir or être +-the past participle (agreement if être) It is used to say something would have happened Eg. I would have gone to the swimming pool.--Je serais allé(e) à la piscine.They (f) would have eaten some chocolate.-- Elles auraient mangé du chocolat.
It is also often used in si clauses along with the pluperfect to describe a hypothetical situation in the past ie. what you would have done if something had taken place:
S’il avait plu, je serais venu(e) chez moi.