IDG Answers is a community of experts who are passionate about technology. Ask a question or answer one below.
FAT was invented for use on floppy disks. Nearly all computers these days recognize FAT and have BIOSs that can boot from FAT. FAT is now used on on devices that hope to be be recognized universally, or that are intended as bootable. CDROMS have FAT-like features to be bootable. Devices like cameras that connect via USB present a FAT interface to make their data more widely availble.
Well, FAT and FAT32 aren't really used for much of anything anymore. The letters F-A-T refer to file allocation table, which was a way to track disc space allocated to files on small hard drives and disks. and FAT32was an upgrade to allow 32 bit cluster addresses back when disk drives started to exceed 512MB, and it allowed a max file size of 4GB. Compare that to NTSF, which allows a max file size of 16TB. In the end FAT and FAT32 are archaic leftovers that are unreliable and don't have the built in security features of NTFS. The only use I've seen recently of FAT and FAT32 is as the subject of this question!