The Façade pattern provides a simplified interface to a complex system, while the Mediator pattern provides a way for components of a system to communicate with each other in a loosely coupled manner. Façade is a one-way communication pattern, while Mediator is a two-way communication pattern.

The Dependency Injection pattern involves passing objects as dependencies to the objects that require them, while the Service Locator pattern involves a central registry that provides objects when requested. The Dependency Injection pattern provides objects to its client as they are needed, while the Service Locator pattern allows objects to request objects they need from a centralized registry.

The Null Object pattern is a behavioral design pattern that provides a default object as a representative of "null" in the context of design patterns.

This means that when designing software, the focus should be on defining the interfaces between different components, rather than the specific implementations of those components. This makes the code more flexible and easier to maintain, as it reduces the amount of coupling between components.

The Decorator design pattern is used to attach additional responsibilities to an object dynamically. This allows for greater flexibility and modularity in the design of a system, as well as the ability to add or remove responsibilities as needed.

The Decorator pattern is used to dynamically add or override behavior of an object, while the Flyweight pattern is used to share objects that are costly to create.

The Null Object pattern is a design pattern in which a special object, called the null object, is used to represent the absence of a value, avoiding the need for explicit checks for null values. The Null Object pattern is used to provide a default implementation of an interface, reducing the amount of error-prone null checks in the code. The Null Object pattern can also be used to simplify the code and reduce coupling by eliminating the need for explicit checks for null values.

CQRS is a pattern that separates the responsibilities of querying data (read) from modifying data (write) into separate models, improving scalability and maintainability of the application.

One example of where Interpreter pattern is used is in compilers, where expressions in a programming language need to be parsed and evaluated. The Interpreter pattern can be used to evaluate the syntax and semantics of a programming language, and generate code or perform other actions based on the results of the evaluation.

The actor classes used in the Memento pattern are: Originator, Memento, and Caretaker. The Originator class is responsible for creating the memento and restoring its state. The Memento class is responsible for storing the internal state of the Originator. The Caretaker class is responsible for maintaining a list of mementos and providing the Originator with the appropriate memento at the appropriate time.

Inversion of Control is a design principle in which the flow of control in a system is inverted. Instead of a system calling components to perform tasks, components are notified when tasks are ready and perform them. This leads to a more flexible and decoupled system, allowing for easier maintenance and testing.

A behavioral design pattern that separates an algorithm from an object structure on which it operates. The pattern allows you to define a new operation without changing the classes of the objects on which it operates.