Monolithic Kernels function with all of the kernel and device drivers inside one address space running in kernel mode. The principle advantage to this approach is efficiency (especially on x86 architectures where a task switch is a particularly expensive operation). Unfortunately, due to it's single address space, a bug in a device driver can bring down the entire system.
===Microkernel===
{{main|Microkernel}}
A Microkernel tries to run runs most of it's services and device drivers in userspace. This can result in an increase in stability and possibly security on machines that have a Memory Management Unit.
