Facade pattern คืออะไร?

FACADE → a SIMPLE interface in front of a COMPLEX subsystem:
  → the subsystem has many components/steps; the facade provides ONE easy interface
  → clients use the simple facade instead of dealing with the complexity directly
  → the facade coordinates the underlying components
→ HIDE complexity behind a clean, easy-to-use interface

  {
  () {
     codec =  ().(file);   
     decoded =  ().(file, codec);
     result =  ().(decoded, format);
     result;       
  }
}
 ().(, );