Video narration
How can CAT turn into FDW? The Caesar cipher is a way to move through the alphabet, replacing each letter with one farther along. The letters aren't random: each one moves the same number of places. For a three-step shift, follow C, then A, then T along the alphabet. After Z, keep counting from A. So the answer is to move C three places forward through the alphabet to F, A to D, and T to W.