And if there’s no heat transfer between systems at all, that’s called thermal equilibrium.

如果系统之间根本没有热传递， 则称为热平衡。

And if there's no heat transfer between systems at all, that's called thermal equilibrium.

如果没有热传递， 在系统中，这称为热平衡。

That pressure and temperature is special, because at thermal equilibrium, water can exist in three phases at once -- ice, liquid, and vapor.

由于热平衡，压力和温度是不同的 水以 3 种形式存在，冰、液体和蒸汽。