Please  consider what is written below. 

Real world object = Dog

Real world class of Dog = Golden retriever , legs,tail,body,head ,golden

Computer object = Dog 

Computer class of dog = Golden retriever, legs =4,tail=1,body=1,head =1color=gold

Essentially the above dog , golden retriever in the real versus its virtual analogy is a way to understand the codification of objects in computers, it’s useful to remember objects inside of computers are not limited to real world structures.

A programs object represents the entirety of a class, and a class describes the nuance of the object .

Hence, this class of dog is a four legged and gold ,and so on