### Design PatternsPlease select 3 design patterns from the following list:- Factory- Singleton- Builder- Observer- Composite- AdapterFor each design pattern, please cover:1. **The short description of the pattern.**2. **When do we use the pattern?**3. **What are the benefits of using the pattern?**4. **Please use a class diagram or code to explain the pattern usage.**

Factory Design Pattern In the factory design pattern, the objects are created without showing the creation logic to the client. The same common interface is used by the client for creating a new type of object. The factory design pattern can be used when a class cannot know the type of objects needed to be created. It can be used when a class needs its subclasses for specifying the objects that it created. The benefits are as follows: The subclasses can select the type of objects to create. It allows loose-coupling by removing the need to bind classes which are specific to the applications into the program. The program can interact solely with the interface or abstract class. Class diagram:Singleton Design Pattern In a singleton design pattern, a class is defined that contains just one instance and allows a global point for accessing it. This design pattern is used in database and multi-threaded applications. It is also used in logging, thread pools, caching, and configuration settings. Benefit: This design pattern saves memory. The object does not get created at every request. Only the single instance gets reused again. Class diagram:Builder Design Pattern In a builder design pattern, a complex object is constructed using simple objects through a step-by-step method. This design pattern is used when the object cannot be created in a single step such as in the de-serialization of a complex object. The benefits are as follows: There is a visible separation between the representation and the construction of an object. It allows modification of the internal representation of objects. There is more control over the construction process. Class Diagram: