Sam is thinking of rooting his phone so he can buy apps from other places. Leo says that he could get Android apps from almost anywhere with a simple check box in settings. Rooting gives the owner super user or admin access to backup the phone, and erase apps and overlays they want the user to have, etc. Should he follow the tutorials he finds on YouTube? Leo says he wouldn't. There's a different procedure for every single phone. He won't want to follow the wrong suggestions and brick his phone.
Leo says that Sam should go to XDA Developers Forums and look up the exact model of the phone he has. Then he should follow the procedures for rooting it very carefully. He should also choose a vanilla ROM.