FUNDAMENTALS OF COMPUTER

Detailed explanation-1: -An optical disk drive uses a laser beam to read the data from the disk as it is spinning. It distinguishes between the pits and lands based on how the light reflects off the recording material.

Detailed explanation-2: -Optical Disc Drive (ODD) An optical disc drive (ODD) in a computer system allows you to use CDs, DVDs, and Blu-ray discs to listen to music or watch a movie. Most drives also allow you to write data to a disc, so you can create your own music CDs, video DVDs or even create of back-up copy of your important data files.

Detailed explanation-3: -The lasers uses in DVD players operate at a wavelength of 650 nm (instead of 780 nm in a CD). 650 nm is visible for the human eye and corresponds to a red color: you’ve probably noticed that there is a red light shining onto the DVD surface inside the player.

Detailed explanation-4: -In the case of CD-R, an infrared laser with a wavelength of 780 nanometers (nm) is employed, while DVD-R uses a red laser with a wavelength of 635 nm.

Detailed explanation-5: -The inner face of CDs is scored with pits several micrometers long, which are arranged in a continuous spiral, and represent recorded data. Laser light is focused on these pits, and data is read by picking up the reflected light. DVDs work according on essentially the same principle.