Facade pattern - request flow

I know that Facade pattern is used to provide the simpler interface by hiding the complex subsystem interactions.

I am referring the below wikipedia uml on Facade pattern:

Are the communications/calls to the Facade are uni-directional requests i.e., only Client1/Client2 sends a request and receive the response from Facade, but the Facade can't initiate a request to Client1/Client2 ?

Am I correct in saying that Facade provides uni-directional (Client -> Facade) request interactions (by simpler interface) where as Mediator facilitates the bidirectional (Client <-> Mediator) interactions across the systems/classes ?