FAT

FAT stands for File Allocation Table. It is the file system used and/or supported by versions of Microsoft Windows, but has been superseded by the VFAT and NTFS file systems.

There are several versions of this file system, with varying cluster sizes: FAT12, FAT16, and FAT32. Each allows for successively larger files and directories to be stored.

FAT is often still used in certain devices, because it is very easy to implement and is very space-efficient for devices lacking in storage capacity.