This excert is taken from r-studios website about FAT & MFT:
http://www.unformat-unerase.com/On a disk, there is a table that stores information about files, such as filenames, folder paths, creation and modification timestamps and, most importantly, where the actual file content is located on the disk and where it begins and ends. For Windows, there are two supported file systems: FAT and NTFS. The file tables for these systems are called the File Allocation Table (FAT) and Master File Table (MFT).
When you format a disk, one of two processes will unfold. When a quick format is performed, the system will create a new file table to replace the existing FAT or MFT. The previous file table will be partially or completely overwritten, destroying information such as filenames, folder structure and the physical location of the data, but the data will still be there. This data will remain untouched until it is overwritten by another application.