Knight forks are fun! As you can see in the following diagram, the knight can attack two or more pieces at the same time. When the knight attacks two pieces at the same time, we call it a knight fork. An attack upon more than two pieces is called a "family fork."
Here's a position from one of my games with black to move. As you can see, a white knight is attacking the black queen. If the Black queen moves forward one square (following the arrow), do you see how white can move the White knight to deliver a family fork?
