A filesystem is a method used to structure data in a disk, and a file is the abstraction used for indicating a piece of self-contained information. If the filesystem is hierarchical, it means that files are organized in a tree of directories, which are special files used for arranging stored files.
Understanding files and filesystems
Operating systems and filesystems
Over the last 50 years, a large number of filesystems have been invented and used, and each one has its own characteristics regarding space management, filenames and directories, metadata, and access restriction. Each modern operating system mainly uses a single type of filesystem.
