Purpose of removing privileges in windows

I am bit confused with user account settings in windows. What is the purpose of changing privileges. Why We should change Admin to a standard user? Why We create an another account and make that account as admin? Is it because We hide actual admin from any malicious threats? Please clarify

It is for the purpose of maximum security and having secured windows system. Any one with windows skills can activate the defualt administrator if not changed or secured with better password. One inportant security messure is always change or secure the defualt privilages.

True… Furthermore you can keep your admin as a guest and add another account as an admin to secure from any threats… Right?