Operating Systems

The four jobs of an OS: manage processes, memory, files, and devices.

What's the difference, when to use each, and the cost of context switches.

Round-robin, priority, fairness — how the OS picks who runs next.

What goes wrong when threads share state — and how mutexes, semaphores, and atomics fix it.

Stack vs heap, paging, the page table, and what 'segmentation fault' really means.

Inodes, directories, mounting, and how journaling keeps your data safe across crashes.

What happens when you press Enter on `cat file.txt | grep cs`.