Chad, Matt, and Rob are three people, kind of like when you have three best friends at school. They are known for making fun videos on YouTube with cool stunts and challenges. They do things like jumping off cliffs with parachutes, riding bicycles off of ramps, and even playing games like hide-and-seek in giant stores.
They have a lot of fans who love watching their videos because they are so entertaining and fun. People love to watch them do crazy things and push the limits of what seems possible. They work really hard to create unique and exciting content that people will enjoy watching.
So, basically, Chad, Matt, and Rob are just three really cool internet stars who like to have fun and make people laugh.