Compact disks types and names

• CD / CD-ROM
  Compact Disk (CD Read Only Memory), frequently used term for ordinary compact disks. Usually, data cannot be written on those disks.
• CD-R
  CD Recordable. Once-time recordable disk. This means that data can written to the disk only once. Data also can be added to already written data using multiple sessions, until the disk space gets exhausted. Data cannot be erased.
• CD-RW
  CD Rewritable. Rewritable disks. Data can be written and fully erased. The disk can be used multiple times. These disks can usually be erased hundred times.

• Capacities of Compact Disc types

  Type	Data max size (MB)	Audio max size (MB)	Time (minutes)
  8 cm	184.57	222.26	21
  	553.71	666.79	63
  650 MB	650.39	783.22	74
  700 MB	703.13	846.72	80
  800 MB	791.01	952.56	90
  900 MB	870.12	1047.82	99

• DVD / DVD-ROM
  Digital Versatile Disc (DVD Read Only Memory). Same as a CD-ROM, but with 6 times capacity.
• DVD-R / DVD+R
  DVD Recordable. Like a CD-R but with a bigger capacity. DVD-R and DVD+R are two different formats, with no significant differences, but some devices can write DVD-R and some other DVD+R only. Most of modern recorders can handle both types of disks.
• DVD-RW / DVD+RW
  DVD Rewritable. Like a CD-RW with a bigger capacity. Pay attention to the difference between "+" and "-" (see description for the DVD-R and DVD+R above).
• DVD-RAM
  DVD Random Access Memory. These disks are comparable to DVD+RW. But instead of them they have a much longer lifetime (approx. 30 years) and can be frequently erased (approx. 10 000 times instead of 1000).
• DVD ... DL
  Double (or Dual) Layer. DVD disks with 2 layers. Capacity of this disks twice more than usual DVD disks.

• Capacities of writable DVD types

  Type	Data max size (GB)
  DVD-R	4.384
  DVD+R	4.378
  DVD-R DL	7.957
  DVD+R DL	7.961

• HD-DVD
  High-Definition Digital Versatile Disc. HD-DVD are comparable with usual DVD with higher capacity. This format has already been abandoned by their creators.
• BD-R
  Blu-Ray Disc Recordable. Like DVD+R, but with a much greater capacity.
• BD-RE
  Blu-Ray Disc Rewritable. Like DVD+RW, but with much greater capacity.