Which law of thermodynamics states that energy cannot be created or destroyed, only converted from one form to another?

Which law of thermodynamics states that energy cannot be created or destroyed, only converted from one form to another?

تھرموڈینامکس کا کون سا قانون یہ بتاتا ہے کہ توانائی پیدا یا تباہ نہیں ہوسکتی، صرف ایک شکل سے دوسری شکل میں تبدیل ہوتی ہے؟
Explanation

The first law of thermodynamics is based on "

the law of conservation of energy, which states that energy cannot be created or destroyed, but can be transferred from one form to another".