Windows 98 is stored on the distribution disks as cabinet (CAB) files. When the Windows 98 disks are created, files are compressed into folders. The Windows 98 files are read in and written out as a continuous byte-stream. The entire stream is compressed and divided into folders as appropriate. Folders can fill one or more cabinets. The following defines the terms used to describe the distribution files.
Cabinet
A file that contains one or more files, usually compressed.
Folder
A decompression boundary. Large folders enable higher compression, because the compressor can refer back to more data in finding patterns. However, to retrieve a file at the end of a folder, the entire folder must be decompressed.
The Windows 98 distribution disks use distribution media format (DMF), which is a special read-only format for 3.5-inch floppy disks that permits storage of 1.7 MB of data.