# Difference between state variable and state function in thermodynamic?

I think these two terms are sometimes used as synonyms and other times as different concepts. Can some explain what is the difference? An example would be good.

Also, can state variable be the state function at the same time? Eg. in ideal gas let's take pressure P... is it a state variable or state function? What about volume V and temperature T?

Pressure $P$ is state variable when we specify equilibrium state of a system by giving numerical value of $P$.
Pressure $P$ is a state function when we discuss how the above value depends on other state variables like $V,T$.