Differences between Abstract Factory Pattern and Factory Method

 The Abstract Factory Pattern and Factory Method Pattern are both creational design patterns, but they have different purposes and structures. Let's explore the key differences between the two:

Abstract Factory Pattern:

1. Intent:

   - Provides an interface for creating families of related or dependent objects without specifying their concrete classes.

   - Deals with multiple types of related objects at once.

2. Components:

   - Abstract Factory: Declares the interface for creating families of products.

   - Concrete Factory: Implements the interface to create specific products for a family.

   - Abstract Product: Declares the interface for a type of product in a family.

   - Concrete Product: Implements the interface for a specific product.

3. Usage:

   - The client uses the abstract factory and abstract products to create families of related objects.

   - Clients can switch between entire families of products by using a different concrete factory.

4. Example:

   - A GUI library that needs to support different types of buttons, text boxes, and other components for various operating systems.

 Factory Method Pattern:

1. Intent:

   - Defines an interface for creating an object but allows subclasses to alter the type of objects that will be created.

   - Deals with creating a single object or a family of related objects through a common interface.

2. Components:

   - Creator: Declares the factory method that returns an instance of a product.

   - Concrete Creator: Implements the factory method to create a specific product.

   - Product: Declares the interface for objects created by the factory method.

   - Concrete Product: Implements the interface for a specific product.

3. Usage:

   - The client uses the creator and products through a common interface.

   - Subclasses override the factory method to produce different variations of the product.

4. Example:

   - A document editor that needs to create different types of documents (PDF, Word) using a common interface.

Key Differences:

1. Scope:

   - Abstract Factory: Deals with creating families of related products.

   - Factory Method: Deals with creating a single product or a family of related products.

2. Number of Products:

   - Abstract Factory: Involves multiple factory methods, each responsible for creating a different type of product.

   - Factory Method: Involves a single factory method responsible for creating one type of product.

3. Client Interaction:

   - Abstract Factory: Clients interact with families of products through abstract interfaces.

   - Factory Method: Clients interact with individual products through a common interface.

4. Extension:

   - Abstract Factory: Typically involves extending families of related products by introducing new abstract factories and products.

   - Factory Method: Involves extending product variations by introducing new concrete creators and products.

In summary, the Abstract Factory Pattern is focused on creating families of related products, while the Factory Method Pattern is focused on creating individual products or families of related products through a common interface. The choice between them depends on the specific requirements and design goals of the application.