Operating Systems
Kernel
Definition
The kernel is the central component of an operating system. It is the first program loaded on start-up and it manages the rest of the startup as well as input/output requests from software, translating them into data-processing instructions for the central processing unit (CPU).
Why It Matters
The kernel has complete control over everything in the system. It handles process management, memory management, and device management, acting as the bridge between applications and the hardware.
Contextual Example
When an application wants to write a file to the hard drive, it doesn't do it directly. It sends a request to the OS kernel, and the kernel handles the low-level details of communicating with the disk hardware.
Common Misunderstandings
- There are different types of kernels, such as monolithic kernels (like Linux) where all services run in kernel space, and microkernels where some services run in user space.
- User applications run in "user mode," while the kernel runs in "kernel mode," which has higher privileges.