FATFAT32

FATFAT32 is not an official file system name; the term is sometimes used informally to refer to the FAT family and, in particular, to FAT32. FAT, or File Allocation Table, is a family of simple, widely supported file systems used since the early days of MS-DOS. The main variants are FAT12, FAT16, and FAT32.

FAT32, introduced with Windows 95 OSR2 in 1996, expands the addressing of data blocks to accommodate larger disks while retaining compatibility with older FAT structures. In FAT32, file allocation is tracked using a 32-bit addressing space for clusters, which allows larger partition sizes than FAT16, while the actual number of usable bits for cluster addresses is effectively 28 bits.

A single file can be up to 4,294,967,295 bytes minus 1; maximum volume sizes depend on sector and cluster choices but reach into the terabytes in typical configurations.

FAT32 is widely supported across modern operating systems, embedded devices, cameras, and USB storage. It has the advantages of broad compatibility and simplicity, but it lacks features found in more modern file systems: no journaling, no native permissions or access control lists, and limited metadata. It is also prone to fragmentation and can be less robust for large numbers of files in a directory.

Because FAT32 cannot natively store files larger than 4 GB, devices that require larger files often use exFAT or NTFS instead. See also FAT, FAT16, FAT32, exFAT.