The Differences Between CDs and DVDs.
October 21st, 2011 | Author: admin
Do you know the Differences Between CDs And DVDs
CDs and DVDs are two completely separate and distinct pieces of technology but to the naked eye they look precisely the same. The biggest difference that you can notice is that a DVD can hold far more data than a CD.
It becomes apparent how the big difference in storage capacity is achieved when you understand how data is written to a CD or DVD. A laser is used to burn pits around a spiral groove in the disc. A laser is an intensely focused beam of light and all lasers have a particular wave length. A smaller wave length will create a smaller pit. A smaller pit obviously takes up less space and ultimately resulting in the ability to store more information in the same amount of surface area.
CDs and DVDs store everything, including audio and video, as a series of ones and zeros which means they are digital data storage mediums. Pits and lands (an area where there are no pits) represent ones and zeros. When the disc drive is reading data the laser is reflected off the lands but not off the pits. Microprocessors in the disc drive take the information from the laser and convert it into a digital format that your PC can easily understand.
Because the spiral groove is narrower on a DVD than a CD it is subsequently longer and able to hold more data. The most common DVD format can hold 4.5GB of data which is approximately six times more than a CD which only holds 700MB. Other DVD formats can hold a lot more because they are double sided or dual layered.
Because a DVD has smaller pits and a laser needs to focus on them the physical make up of a DVD is different to a CD. This is 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.
DVD technology also has a much faster rate of reading and processing data. The average 52X CD-ROM drive reads data at 8MB a second, while a 24X DVD drive reads at 32MB a second.
With Blu-Ray being the new kid on the block and because it has such a massive storage ability DVDs will slowly be phased out as will CDs. CDs will be available for a while yet but as Blu-Ray prices come down and storage needs continually spiral upwards I can’t see them lasting forever. For more related information on CDs and DVDs in regards to packaging and marketing check out the following website Packaging CDs and DVDs.
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