The engine that an operating system or program uses to organize and kept track of files. More specifically, the logical structures and software routines used to control access to the storage on a hard disc system and the overall structure in which the files are named, stored, and organized. The file system plays a critical role in computer forensics because the file system determines the logical structure of the hard drive, including its cluster size. The file system also determines what happens to data when the user deletes a file or subdirectory..”