How Operating Systems Actually Work

Every program runs on top of a kernel making decisions for it: which thread gets the CPU, which pages stay in memory, when a write really reaches disk. This path opens that layer up. You will learn what a process actually is and what a context switch costs, how virtual addresses become physical ones through page tables and the TLB, what happens when code crosses into kernel mode and why that crossing is expensive, and how the page cache and fsync decide whether your data survives a crash. It closes on containers as ordinary kernel features rather than magic.