About FAT filesystem

FAT is the acronym for File Allocation Table which is one of the best known methods to keep track of the contents of a disk used by the Windows operating systems. It was invented in 1977 by Microsoft and initially was the solution to store data on floppy disks.
The FAT filesystem was used by the MS-DOS (Microsoft Disk Operating System), developed by Microsoft. We can distinguish three types of File Allocation Tables:

FAT12 – it is a 12-bit binary file system and the oldest FAT type
FAT16 – it uses a 16-bit binary file system (there are still PCs running Windows 3.1 or 95 in which the hard drive uses FAT16 filesystem)
FAT32 – an improved file allocation table which uses 28-bit binary system