Operating systems

File Systems

Overview

A file system is the method an OS uses to organize and store files on a storage device, determining where files are saved and who can access them.

Key concepts

  • NTFS (Windows)
  • FAT32 / exFAT (cross-compatible)
  • ext4 (Linux)
  • APFS (macOS)

How it works

Overview

A file system is the method an OS uses to organize and store files on a storage device — it determines where files are saved, who owns them, and who is allowed to access them.

Common File Systems

File systemUsed byNotes
NTFSModern WindowsSupports large files, permissions, journaling, encryption, compression.
FAT32Older/very compatible devicesWorks with game consoles, cameras, USB drives; can't store individual files over 4GB.
exFATUSB/external drivesSupports large files, works well across Windows and macOS.
ext4Most Linux systemsSupports Linux permissions, journaling, large storage volumes.
APFSModern MacsApple File System — supports encryption, snapshots, and space sharing between volumes.