Home | Recreation And Leisure | Entertainment

Differences Between CD's

By: Alex De Mostafa

Read More About Entertainment

Even though both CD and DVD disks have the same media size and shape, the things they have in
common ends there. There are many different things between the two, such as what they hold
and how much they hold.

Data pits and lasers

A disc has microscopic grooves that will move along in a spiral around the disc. CDs and DVDs both have these grooves, with laser breams applied to scan these very grooves.

As you may know, digital information is represented in ones and zeroes. Inside of these discs, very tiny reflective bumps known as lands and non reflective holes known as pits, which can be
found beside the grooves, reflect both the ones and the zeroes of digital information.

By reducing the wave length of the laser to 625mm or more infrared light, DVD technology has
managed to write in smaller pits when compared to the standard technology of CD. This will
allow for a greater amount of data per track on the DVD. The minimum length allowed for a
pit in a single layer DVD-R is .4 micron, which is obviously more than the .0834 micron that a
CD offers.

The tracks of a DVD are narrower as well, which allows for more tracks per disc, which also
translates into more capacity than a CD. The avaerage single layer DVD holds 4.5 GB of data,
while a CD holds a mere 700 MB.

Layers

As stated above, a DVD has smaller pits and the lasers need to focus on them. This is actually
achieved by using a thinner plastic substrate than in a CD, which means that the laser needs
to pass through a thinner layer, with less depth to reach the pits. It's this reduction in
thickness that's responsible for the discs that were only 0.6mm thickness - which is half
that of a CD.

Data access speed

DVDs will access data at a much faster rate than a CD can. The average 32X CD-ROM drive reads
data at 4MB a second, while a 1X DVD drive reads at 1.38MB a second. This is even faster than
an 8X CD drive.

Universal data format

The recording formats of CDs and DVDs are quite different, as DVDs use UDF, or the Universal
Data Format. This format allows data, video, audio, or even a combination of all three to
be stored in a single file structure. The advantage to this is any file can be accessed
by any drive, computer, or even consumer video. CDs on the other hand aren't compatible with
this format.

Article Source: http://depositarticles.com/

Joseph Campbell also writes on topics such as Live CD, What is a Home Theater System Visit Differences Between CD's

Please Rate this Article

 

Not yet Rated

Click the XML Icon Above to Receive Entertainment Articles Via RSS!
Additional Articles From - Home | Recreation And Leisure | Entertainment
Sign Up for a free account.
Our other websites
All about SEO
Beauty Tips Forum
Submit Articles
Member Login
Link Us
Submission Guidelines
Ezine Notifications
Article RSS Feeds
Sitemap
New Stuff
About Us
Developer
Good shopping portal
Link to Us
Contact Us
Privacy Policy
Terms of Service

counter easy hit

Powered by Article Dashboard