Zeroth Law of Thermodynamics
It states that "If a Body 'A' is in thermal equilibrium with body 'B' and body 'B' is in thermal equilibrium with body 'C', Seperately.Then, Body 'A' and Body 'C' in Thermal Equilibrium."
* This law gives us the concept of temperture.
* In Zeroth law, Body act as a thermometer.