What is it

Modern operating system uses virtual memory to provide separate address spaces or separate regions of a single address space.

• these spaces are kernel space and user space.
• Linux, macos, windows all utilizes kernel space

These separations provide memory protection and hardware protection from malicious or errant software behavior.

kernel space is strictly reserved for running a privileged operating system kernel, kernel extensions, and most device drivers.

user space is the memory area where application software and some drivers execute.

• typically one address space per process.

User Space

All code that runs outside the operating system's kernel.

• Refers various programs and libraries that the operating system uses to interact with the kernel.
• Each user space process runs in its own virtual memory space
• Unless explicitly allowed, cannot access the memory of other processes.