[StephenCanis]

You are right - what Alex did is called "free soloing" which means climbing with nothing attached to the wall. Freeclimbing means you climb while harnessed in so if you fall you (hopefully) don't die. Originally people "aid climbed" the wall where you drill bolts into the wall and hoist yourself up.

This also explains why Alex can climb it so much faster. No ropes to worry about on the way up.

Check out the movie valley uprising on Netflix if you want to learn more.