What is Kernel?
A kernel is the central module of an operating system (OS). Each and every OS has a kernel. Basically, UNIX is a type of kernel, around which the operating system has been created. It is the kernel that loads first and simultaneously remains in main memory. It is also responsible for providing all the essential services that are required by other parts of the operating system and applications.
The kernel is typically stored in protected memory to avoid it accidently being overwritten. The kernel is responsible for memory management, process and task management, and disk management. It also connects the system hardware to the application software.