What is the way of Cain, the error of Balaam and the gainsaying of Core (Korah)?

> Jude 1:11 (KJV): Woe unto them! for they have gone in the way of Cain, and ran greedily after the error of Balaam for reward, and perished in the gainsaying of Core. > > Jude 1:11 (NIV): Woe to them! They have taken the way of Cain; they have rushed for profit into Balaam's error; they have been destroyed in Korah's rebellion. Who is “them” mentioned above and what is the way of Cain, the error of Balaam and the gainsaying of Korah?