Connected Car Operating System (ccOS) is an in-vehicle operating system (OS), a core platform technology for connected cars. It is characterized by controlling various hardware like the OS of a smartphone and providing a base environment for application software. Of course, since ccOS is focused on the vehicle environment, it not only manages the external network, but also participates in the vehicle's internal network. In addition, it is different from other OS in that it considers the cockpit environment, such as the infotainment system, separates the network for vehicle safety, and has a specialized security system.