Fat = (File Allocation Table) – The file system originally used by DOS (actually,the Windows XP implementation is an extension of Virtual FAT [VFAT], which includes support for long file-names and 4 GB files and Volumes.) Windows XP FAT is also known as FAT16.
FAT32 – An enhancement of the FAT 16 file system developed for Windows 95 )SR2, and included in Windows 98. Windows XP includes support for FAT32 primarely to gain the 32 GB file and file size improvement over FAT16. FAT32 volumes created by Windows 95 OSR2 or Windows 98 can be mounted over Windows XP.
New Technology File System (NTFS) – A high performance , secure, and object oriented file system introduced in Windows NT. This is the preferred file system for windows XP, Windows 7 and Vista.