Euthyphro - (Socrates asks what is Piety/Holiness?)

In this Plato conversation called Euthyphro, Socrates met Euthyphro outside the court of Athens as Socrates was coming out from hearing charges of impiety against him, and Euthyphro was on his way to court to prosecute his own father for unintentionally killing a murderous hired hand.

Since Socrates was accused of impiety and Euthyphro was prosecuting his father for impiety, Socrates was curious to learn from Euthyphro what piety is.