**Design patterns** are the programming best practices followed by software developers. They were created as a solution to commonly occurring problems faced during software development. They are *repeatable solutions* to problems that generally arise in everyday software designing.
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# Design pattern categories

There are a total of 23 patterns which are classified into the following three categories:

   **1. Creational patterns:** These patterns are related to classes creation and inheritance. They may also include patterns related to object creation.

   **2. Structural patterns:** These patterns are how classes are composed; the composition of objects, classes in order to create interfaces.

   **3. Behavioral patterns:** These patterns are related to how objects communicate with one another within the software.


The following table lists down each design pattern with respect to the category it falls in:

# Why use design patterns
Design patterns simplify the process of software development by providing a basic structure for the problem at hand. Following are some of the advantages of using design patterns in your code:

* Provide a generic solution, i.e. code can be reused in different projects.
* Design patterns are a proven solution for common problems that arise in code.
* Using design patterns makes it easy to test the system as they are already proven solutions.
* All design patterns follow specific, self-descriptive naming conventions, which enhances the readability of the code. 

Design patterns in Java

Design patterns offer repeatable solutions to common software problems. They are grouped into creational, structural, and behavioral patterns. They enhance code reuse, testing, and readability.