What is the role of the FAT (File Allocation Table) in file systems?

The File Allocation Table (FAT) in file systems, such as FAT12, FAT16, and FAT32, serves as a critical data structure that maps out the allocation of disk space to files. It tracks which clusters (contiguous blocks of storage) are used and which are free, allowing the operating system to locate and access files efficiently. The FAT contains entries for each cluster on the disk, indicating whether a cluster is free, allocated to a file, or reserved for system use.