What is the primary purpose of constitution in a political system?

What is the primary purpose of constitution in a political system?

سیاسی نظام میں آئین کا بنیادی مقصد کیا ہے؟
Explanation

The primary purpose of constitution in a political system is to clearly define the rights of citizens.

The purpose of a constitution is mainly to set down rules and regulations for what the government can and cannot do and how it should function and be structured.