• They fall into structural pattern categories.
• Façade pattern sits on the top of group of subsystems and allows them to communicate in a unified manner.
• The façade takes care of orchestration part and present more simplified interface to the client.

Example:

In a typical online shopping cart when a customer places any order following things happens.

• Get Product Details
• Make Payment
• Print Invoice

The above example can be implemented using Facade pattern as follows:

1. The main class (clsOrder) is exposed to the client which internally takes care of calling other related classes  (clsProduct, clsPayment, clsInvoice).
2. The clsOrder class acts as a facade class which takes care of orchestration by calling other related classes internally.