filesystem
also: fs, file system
A filesystem is the method and data structure that an operating system uses to organize, store, and retrieve files on storage devices. It defines how data is named, accessed, and managed on disk or other media.
A filesystem is a hierarchical system that organizes data into files and directories (folders) on a storage device like a hard disk or SSD. The operating system uses a filesystem to keep track of where each file is physically stored on the device, manage permissions, and handle read/write operations efficiently.
Linux supports many different filesystems, each with different features and trade-offs. The most common modern filesystems are ext4 (stable and widely used), btrfs (newer with advanced features), and XFS (optimized for large files). Other filesystems like FAT32 and NTFS are used for USB drives and Windows compatibility.
Every filesystem has a root directory (/) and a tree structure of subdirectories. For example, the path /home/user/documents/report.txt represents a file named report.txt nested in multiple directories. You can view your current filesystem with df -h or check filesystem types with mount.