A lab here starts a machine for you in the browser, and it comes up fast. The page walks you through the steps, and you try them on that machine, on the real software. You install nothing. When the lab ends, the machine is gone, and nothing was changed on your own computer.
Katacoda worked this way. Runlab is the same kind of site: a lab is something you do, not a page you only read.
The labs are free. Sign in with Google and launch one from the front page. Some of them offer a badge when you finish.
Eitan Suez built runlab, with help from Grok.