Following the file allocation tables is the root directory. This area contains 32-byte entries that describe files, subdirectories, and the volume label (if present). The size of the root directory is determined when the disk is initialized, as is described in the BIOS parameter block, at offset 0X0011 of the boot sector of the disk. See The structure of the disk directory.
The structure of the disk directory
DOS filenames are made of two parts: