You check into a hotel. You want a room sorted, a taxi booked, dinner reserved, and a wake-up call.
Do you hunt down the housekeeping department, then the transport desk, then the kitchen, then the operator, one at a time? No. You call reception and say "sort all this out." Reception knows who to call behind the scenes. You talk to one person instead of five.
That's the Facade pattern: one simple front door that hides a messy, complicated system behind it.
The problem: the caller has to know everything
Say placing an order actually involves four subsystems, in a specific order:
