Silly Buffy TVS question

Okay, so I’ve seen a good deal of the show, but nowhere near the entire thing. Today, there was an episode from the first season where Darla frames Angel to look like he attacked Buffy’s mom. When Buffy’s going after him, Giles makes the comment that “He’s faced The Three…”

Who/What are “The Three”?

The Three were vampire hitmen used by the Master to try and kill Buffy and Angel. They don’t succeed and are executed by him for their failure.