SOLID Design Principles

In the Single Responsibility Principle (SRP), each class should be responsible for a single part or functionality of the system.
In the Open Closed principle (OCP), software components should be open for extension but closed for modification.
In the Liskov Substitution Principle (LSP), objects of a superclass should be replaceable with objects of its subclasses without breaking the system.
The Interface Segregation Principle (ISP) makes fine-grained interfaces that are client specific.
The Dependency Inversion Principle (DIP), ensures that the high-level modules are not dependent on low-level modules. In other words, one should depend upon abstraction and not concretion.