What is a file system and what functions does it provide?

A file system organizes and manages how data is stored and retrieved on storage devices. Functions include: file naming and organization (directories, hierarchies), space management (allocation, free space tracking), metadata management (permissions, timestamps, ownership), data integrity (journaling, checksums), and providing access methods (sequential, random). Common file systems: ext4 (Linux), NTFS (Windows), APFS (macOS), ZFS (enterprise).