A stupid question as a beginner

So as the title says, I am complete noob to both MotoGP and bikes in general. You can compare me to a man living under rock in terms of motorcycles cause cars were always my interest. But as I am getting into MotoGP, I am slightly confused about few things. How the riders and teams find necessary grips on motorcycles? How do they set up their bikes on different circuits and what they do to change setups? As it says, some technical stuff is welcomed and ELI5.

So as the title says, I am complete noob to both MotoGP and bikes in general. You can compare me to a man living under rock in terms of motorcycles cause cars were always my interest. But as I am getting into MotoGP, I am slightly confused about few things. How the riders and teams find necessary grips on motorcycles? How do they set up their bikes on different circuits and what they do to change setups? As it says, some technical stuff is welcomed and ELI5. http://ifttt.com/images/no_image_card.png