Introduction
Every time you save a document, download a photo, or install an application, you’re trusting a filesystem to keep your data safe. Think about it—filesystems are this invisible layer between your applications and raw storage hardware. They turn a sea of numbered blocks into the familiar world of files and folders that we all take for granted.
But what exactly does a filesystem do? And what makes it so tricky to get right? In this series, we’re going to explore filesystems like FAT32, ext4, Btrfs, and others. But before we get there, I want to build a solid foundation with you. We’ll start at the very bottom—how storage hardware actually works—and work our way up to the abstractions that filesystems provide.