in python, If we write 2 different varibles with same values then why

A variable is a container that needs to have memory associated with it. If you have 2 variables, it will require 2 memory spaces. Think of this. You have 2 glasses with 200ml water in them. Even though the water quanitity is same (200ml), you're still using 2 glasses, means you will need space to store 2 glasses. Same idea. It is not just Python. All languages work like this.