The function of the kernel in an operating system is to manage system resources and facilitate communication between hardware and software. It acts as the core component, controlling process management, memory management, file systems, and device management. The kernel operates in a privileged mode, ensuring that system security and stability are maintained. It enables applications to perform tasks without needing to understand the complexities of the hardware, effectively abstracting these details. A well-designed kernel is crucial for the overall performance and responsiveness of an operating system.