Definitions and the Zeroth Law

Much like other scientific disciplines, thermodynamics also has its own vocabulary. For instance, while dealing with objects composed of very large numbers of particles, one might use terms like thermodynamic system; adiabatically isolating, and adiabatically enclosing, walls; adiabatic and nonadiabatic enclosures; conducting and/or diathermal walls; isothermal, isobaric, isochoric, quasistatic, reversible, and irreversible processes; state functions and state variables; thermodynamic equilibrium and, of course, temperature in its various representations.