FAT file system was supported by almost all personal computer operating systems because the computer performance was limited and not complicated at that time. This feature makes it an ideal file system for floppy disks and memory cards, and is also suitable for data exchange in different operating systems. Now generally speaking, fat refers to FAT32.
But FAT has a serious disadvantage: when a file is deleted and new data is written, FAT will not organize the file into complete fragments and then write them. After long-term use, the file data will gradually become scattered and the reading and writing speed will slow down. Defragmentation is a solution, but it must be reorganized frequently to keep the efficiency of the FAT file system.
FAT32 is a partition format. This format uses a 32-bit file allocation table, which greatly enhances its ability to manage disks and breaks through the limitation of 2 GB per partition in FAT 16.
Because the production cost of hard disk is decreasing, the capacity is increasing. After using the partition format of FAT32, we can define a large hard disk as a partition without dividing it into several partitions, which greatly facilitates the management of the disk. However, because FAT32 partition can't store a single file larger than 4GB, its performance is poor, and it is prone to disk fragmentation. It has been replaced by the better NTFS partition format.
Before the introduction of FAT32 file system, the file system commonly used by PC was FAT 16. The systems based on MS-DOS and Win 95 all adopt FAT 16 file system. Under Win 9X, the maximum partition supported by FAT 16 is 2GB.
We know that computers store information in an area called "cluster" on the hard disk. The smaller the cluster used, the higher the efficiency of saving information. In the case of FAT 16, the larger the partition, the larger the cluster and the lower the storage efficiency, which will inevitably lead to the waste of storage space. And with the continuous improvement of computer hardware and application, the FAT 16 file system can no longer meet the requirements of the system. In this case, the enhanced file system FAT32 is introduced.