Command is a behavioral design pattern that encapsulates a request as an object that contains all the information about the request, including requests for queues or logs, allowing for much more complex architectures.
Singleton is a creational design pattern that lets you ensure that a class has only one instance, while providing a global access point to this instance.
Adapter is a structural design pattern that allows objects with incompatible interfaces to collaborate. The object that joins these unrelated interface is called an Adapter.