FAT Full Form is File Allocation Table. A file allocation table (FAT) is a system developed for hard drives that used 12 or 16 bits originally for cluster entry into the file allocation table. It is used to manage files on hard drives and several computer systems. It is often found in digital cameras and portable devices. The FAT file system is supported by mostly all OSs on personal computers (PCs). Files in hard drives are stored in the form of clusters. These clusters are scattered over the disk.
The operating system creates an FAT for the new file that records the location of each cluster and its sequential order. FAT offers good performance even for light-weight implementations, but fail to deliver the same performance & reliability on some modern file systems. It is used to store file information and improve the life of a hard drive.
The FAT file system is designed to reduce the amount of seeking, thereby minimizing the wear and tear on the hard disc. FAT is also used for storing information on portable media such as memory cards. FAT is designed to support sub-directories and hard drives. FAT 16 is older version of FAT in Windows 95 and the latest version is FAT 32 (Windows 98).