Operating Systems / Linux
Fundamentals
A closer look at Fundamentals.
A short history of Unix and Linux
Unix began as a research operating system at Bell Labs and grew into a family of standards and kernels. This overview traces BSD and GNU, the 1991 Linux kernel, the GPL, how distributions bundle the stack, and where Linux runs today—from servers to Android.
Linux distributions and Debian
A distribution turns the Linux kernel into an installable system with policies, packages, and support timelines. This overview explains what distros add, how Debian's stable, testing, and unstable branches work, common derivatives, and how other families compare when you choose a base.
The Linux kernel
The kernel is the privileged core that talks to hardware and exposes system calls to programs. This overview separates kernel space from user space, explains monolithic design and loadable modules, and covers scheduling, memory, versions, and how Debian ships kernel packages.