6a5e3fac____Understanding_the_Drive_Map__Explanation
[Color] Purple [Description] Reserved MFT Space [Explanation] 
This section is reserved for the Master File Table (MFT), which is a database that stores information about every file and folder on this hard drive. The MFT is used for NTFS-formatted drives only. Defraggler can defragment the MFT as well, but it cannot move the MFT's starting position.
Piriform - Understanding the Drive Map
Explanation