What is difference between refrigerator and air conditioner?

An air conditioner has a fan that will push the air into the room you want to cool. The exhaust needs a path outside (via window or outdoor AC unit), otherwise the air condition won't be doing anything except heating and cooling the room at the same time.

A fridge will just cool the interior of its insulated container.

Functionally, its the same idea: cool air in one place by heating air in another.