Before we start discussing design principles, let's think about what we mean by Design Principles in software development. When we develop software, we first design its architecture, and then we start writing its code. We want to write our code in such a way that it generates no bugs, or so it is easy to find bugs if there are any. We also want the code to be easily understandable when we read it and we want it to be structured in such a way that it can be changed later if required. Although it is difficult how to write the best-possible code, there are various principles in software development that have been developed by experienced computer scientists. Using these, developers can write very clean code.

The software developer Robert C. Martin, also known as Uncle Bob, came up with five software design principles. These principles are so effective and helpful for developers that they have become a norm in the software industry. Collectively, they are known as the SOLID principle, which represents the following different definitions:

• S stands for the Single Responsibility Principle

• O stands for the Open Close Principle

• L stands for the Liskov Substitution Principle

• I stands for the Interface Segregation Principle

• D stands for the Dependency Inversion Principle

Let's discuss these principles one by one.