_Technically_ "potential difference" is the difference in electrical potential, i.e. $\Delta V$, not the difference in electrical potential energy, $\Delta U$. Potential difference ($\Delta V$) is also called voltage, in certain contexts.

However, many people and sources are sloppy about their terminology, and they will say just "potential" when they really mean potential energy. An expert could tell which is meant (or that it doesn't matter, if that is the case) based on context, but it can easily confuse beginners.