'''File Allocation Table''' ('''FAT''') is a [[file system]] developed for personal computers and was the default file system for the [[MS-DOS]] and [[Windows 9x]] operating systems.<ref>{{cnCite web |title=File Allocation Table (FAT): What It Is, Types, Versions, Advantages & Disadvantages |url=https://www.includehelp.com/operating-systems/file-allocation-table-fat.aspx |access-date=September2025-06-01 2024|website=www.includehelp.com}}</ref> Originally developed in 1977 for use on [[floppy disk]]s, it was adapted for use on [[Hard disk drive|hard disks]] and other devices. The increase in disk drive capacity over time drove modifications to the design that resulted in versions: [[#FAT12|FAT12]], [[#FAT16|FAT16]], [[#FAT32|FAT32]], and [[exFAT]]. FAT was replaced with [[NTFS]] as the default file system on Microsoft operating systems starting with [[Windows XP]].<ref>{{cite web |url=https://windows.microsoft.com/en-us/windows-vista/comparing-ntfs-and-fat-file-systems |title=Comparing NTFS and FAT file systems |publisher=Microsoft |access-date=2014-01-27 |archive-date=2016-06-20 |archive-url=https://web.archive.org/web/20160620004455/http://windows.microsoft.com/en-US/windows-vista/Comparing-NTFS-and-FAT-file-systems |url-status=live }}</ref> Nevertheless, FAT continues to be commonly used on relatively small capacity [[solid-state storage]] technologies such as [[SD card]], [[MultiMediaCard]] (MMC) and [[eMMC]] because of its compatibility and ease of implementation.<ref>{{Cite web |title=A brief introduction to FAT (File Allocation Table) formats |url=http://www.wizcode.com/articles/comments/a-brief-introduction-to-fat-file-allocation-table/ |url-status=dead |archive-url=https://web.archive.org/web/20150925082826/http://www.wizcode.com/articles/comments/a-brief-introduction-to-fat-file-allocation-table/ |archive-date=September 25, 2015 |access-date=2015-09-24 |website=www.wizcode.com |df=mdy-all}}</ref>
