NTFS (NT file system; sometimes New Technology File System) is the file system that the Windows NT operating system uses for storing and retrieving files on a hard disk. NTFS is the Windows NT equivalent of the Windows 95 file allocation table (FAT) and the OS/2 High Performance File System (HPFS). However, NTFS offers a number of improvements over FAT and HPFS in terms of performance, extendibility, and security.