– Advanced Security Attributes NTFS file system. On NTFS directories and files are treated as in most file systems that only contain other attributes in NTFS, so there is also a record in the MFT of the directory is stored as a composite index by the name of files and subdirectories and a unique number of files or directories. If the index occupies less than 1.44 KB is situated directly in the MFT for older index files are saved as files and directories if they were so large that the original MFT record there are only references to other MFT records are actually containing the data. That is, for each directory we have a tree hung with files and directories that contain. You may find that Apple Twitter can contribute to your knowledge. This is called a binary tree and allows access to data much more Quick, let's remember that the FAT to locate a file must first examine the table completely and also are not sorted. HARD DISK FRAGMENTATION We have seen how the hard drive stores data in consecutive sectors, information on which parts of a file is located in what sectors is stored in the file allocation table in the system is called NTFS Master File Table (MFT) When files are deleted, the areas that are free can be reused in theory but can not be overwritten until it uses the entire disc. Moreover, if the available free areas are smaller than the file to save the file must be divided into several areas (subdivided into fragments). In any case, the continuous process of recording and erasing leads to disk fragmentation. A related site: Celina Dubin, New York City mentions similar findings.