A kernel is the core of an operating system. It is responsible for managing the resources of the computer, such as memory, processors, and peripherals. It also provides an interface between the user and the hardware. An example of a kernel is the Linux kernel.
A shell is a program that provides an interface for users to interact with the operating system. It interprets commands from the user and passes them to the kernel for execution. An example of a shell is the Bash shell.