Monolithic kernel
OS that runs entirely in kernel-mode / From Wikipedia, the free encyclopedia
A monolithic kernel is an operating system architecture with the entire operating system running in kernel space. The monolithic model differs from other architectures such as the microkernel[1][2] in that it alone defines a high-level virtual interface over computer hardware. A set of primitives or system calls implement all operating system services such as process management, concurrency, and memory management.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/d/d0/OS-structure2.svg/640px-OS-structure2.svg.png)
Device drivers can be added to the kernel as modules.
Monolithic architecture kernel examples: Unix (including Linux), MS-DOS, Windows 9x.