Stands for "Virtual File Allocation Table." Older Windows operating systems (Windows ME and earlier) used a file system called "FAT" or "FAT32." The file system is what the operating system uses to organize and access files on the hard drive. VFAT, introduced with Windows 95, was an improvement to the basic FAT file system, allowing more information to be stored for each file. While the FAT file system can only store 8 characters for each file name, VFAT allows for file names up to 255 characters in length. Personally, I use the term VFAT to refer to the size of my cat.