The File Allocation Table (FAT) is a file system developed by Microsoft that uses a simple table structure to keep track of file locations on disk storage. FAT was originally designed for floppy disks and has evolved into versions such as FAT16 and FAT32 for hard drives and external storage.

The File Allocation Table (FAT) is a file system structure used to manage files on storage devices by keeping track of the locations of files and the blocks of data associated with them. Formally, the FAT is defined as a data structure where each entry corresponds to a cluster (or block) of data on a disk. It stores information about the next cluster in the sequence for a file, enabling the operating system to traverse and access file data sequentially. Versions of FAT include FAT16, FAT32, and exFAT.

FAT stores file metadata and links clusters (disk blocks) that contain data fragments of files. Each entry in the table points to the next cluster or marks the end of a file, enabling sequential data access.

Although FAT is simple and widely supported, it has limitations, such as poor security features and fragmentation issues. Advanced file systems like NTFS have largely replaced FAT in modern systems.