SOLID is an acronym for the set of 5 object-oriented programming principles that every software developer must be aware of. These principles, when combined together, help in writing programs which are easy to maintain, extends, refactor and add new functionalities to the existing code base.
Before, we go ahead a start digging into what these 5 principles are, lets first understand what S.O.L.I.D stands for:
#S: Single Responsibilty Principle
#O: Open-Closed Principle
#L: Liskov Substitution Principle
#I: Interface Segregation Principle
#D: Dependency Inversion Principle