Just google parkour. I guess "free-running" was the term most advertised in america.
I cant really explain it.
I guess it's just running, without anything stopping you. Using the most efficient ways to get up and over anything in your way. Literally anything.
I just started this year too. But I've had the fucking time of my life doing it! It's seriously amazing, and is an extreme workout on your entire body as well. I love it man.