The function of an operating system kernel is to manage system resources and facilitate interactions between software applications and hardware components. The kernel acts as a bridge between programs and the physical machine, handling tasks such as memory management, process scheduling, and device drivers. It ensures that applications can execute efficiently by allocating necessary resources, while also maintaining system stability and security. By managing communication between different parts of the computer, the kernel plays a critical role in ensuring overall system performance and functionality, making it a core component of any operating system.