Your first algorithm

Four moves that come back home.

An algorithm is a short sequence of moves that you can repeat. Here's the most famous one. R, U, R prime, U prime. A few pieces moved, but most of the cube is still solved. Now here's the surprise. If you repeat it six times in a row, everything goes back exactly to where it started. That's the big idea behind solving. An algorithm moves a few pieces in a known way, while everything else comes back home.

Your turn. Do R, U, R prime, U prime, once.

Well done. Notice which pieces changed, and which stayed.

Now keep repeating it until the cube is solved again. It should take five more times.

Solved. You've just felt how an algorithm works.