True.
Our social life and well being is dependent on others and mutual co-operation has a very important place in it.
The same is true about society, and it applies to different nations as well. There are many independent nations in the world, like India.
Some exchange and interaction goes on among these nations on a regular basis.These independent states also enter into treaties with each other.
A system of all these independent, sovereign states that emerges is called an International System.