OOPs ?

• Object Oriented Programming is based on the idea of “objects“. 
• In programming everything is identified as an object and its properties and behaviors to solve a problem.
• Ex:   Chair 
•       properties are Type, shape, color, size, width,weight
•       behaviors are changed the width, color, position

• SOLID is  set of of Principles which helps to design a “Solution” for a object oriented programming concepts
• SOLID is basically design principles used to create great software Architecture to develop a better software

To conclude SOLID is a principle helps in Oops concepts. SOLID principle will help us to write loosely coupled code which is highly maintainable and less error prone.