What is a design pattern?
Design patterns : Design patterns represent the best practices Design patterns are solutions to general problems that software developers faced during software development. Gang of Four (GOF)? : In 1994, four authors Erich Gamma, Richard Helm, Ralph Johnson and John Vlissides published a book titled Design Patterns - Elements of Reusable Object-Oriented Software which initiated the concept of Design Pattern in Software development. These authors are collectively known as Gang of Four (GOF) According to these authors design patterns are primarily based on the following principles of object orientated design: Program to an interface not an implementation Favor object composition over inheritance Usage of Design Pattern : Common platform for developers Best Practices Types of Design Patterns : Creational Patterns : These design patterns provide a way to create objects while hiding the creation logic, rather than instantiating objects