Question

Discuss the functioning of DVDs.....

Answer 1

     DVD is a Digital Video Disc or Digital Versatile Disc.  That is used for recording and retrieving digital data.  It is a rewritable medium.  The data is stored using optical technology.  The surface of the optical disc is burned by a precisely controlled thin high energy single frequency laser beam to record data bits.  A DVD has a higher storage capacity than CD-ROM and it appears similar to a CDROM disk.
    That was invented by Sony Toshiba and Philips in 1995.  A DVD player is needed to use DVDs.  A software that can interact with DVD is needed.  DVDs can be DVD-R (read only) or DVD+-RW (rewritable).  Data can be recorded and erased and rewritten thousands of times.
   The DVD contains tracks around the center.  Along the tracks in a circular path, data is burnt by laser beam.  DVD uses only one side of the disk.   Light emitting laser diodes of wavelength 650 nm (red color) light is used.

     This is smaller than that used for a CDROM.  The recording head can read or write data at the rate of 20 X 1.385 kB/s.
    Now, DVD- video and DVD-Audio formats are standards for video and audio data.  The optical disks are rotated inside the drive at a constant linear velocity ie., CLV.  For example , the drive rotates at around 500rpm when reading the outermost track and at 200 rpm when reading the innermost track.  The data read write rates remain same for all the tracks.  On the other hand, A hard disk drive rotates at a constant angular velocity CAV.

Answer 2

Answer:

     DVD is a Digital Video Disc or

Digital Versatile Disc.  That is used for recording and retrieving digital

data.  It is a rewritable medium.  The data is stored using optical

technology.  The surface of the optical disc is burned by a precisely

controlled thin high energy single frequency laser beam to record data bits.

 A DVD has a higher storage capacity than CD-ROM and it appears similar to

a CDROM disk.

    That was invented by Sony Toshiba and Philips in 1995.

 A DVD player is needed to use DVDs.  A software that can interact

with DVD is needed.  DVDs can be DVD-R (read only) or DVD+-RW

(rewritable).  Data can be recorded and erased and rewritten thousands of

times.

   The DVD contains tracks around the

center.  Along the tracks in a circular path, data is burnt by laser beam.

 DVD uses only one side of the disk.   Light emitting laser diodes of

wavelength 650 nm (red color) light is used. 

     This is smaller than that used for a CDROM.  The recording

head can read or write data at the rate of 20 X 1.385 kB/s.

    Now, DVD- video and DVD-Audio

formats are standards for video and audio data.  The optical disks are

rotated inside the drive at a constant linear velocity ie., CLV.  For

example , the drive rotates at around 500rpm when reading the outermost track

and at 200 rpm when reading the innermost track.  The data read write

rates remain same for all the tracks.  On the other hand, A hard disk

drive rotates at a constant angular velocity CAV.