Do you know the Differences Between CDs And DVDs
Even though both CD and DVD disks have the same media size and shape, the things they have in common end there. There are many different things between the two, such as what they hold and how much they can hold.
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.
Digital data is data that is stored as a series of ones and zeros. DVDs and CDs are digital data storage mediums so everything, including audio and video, is stored as ones and zeros. The pits and lands (where there are no pits) on the DVDs and CDs represent ones and zeros. The laser light will reflect off the lands but not off the pits when the disc is being read. The information from the laser is converted by a microprocessor into digital data that a computer can understand.
The tracks of a DVD are narrower as well, which allows for more tracks per disc and translates into more capacity than a CD. The typical single layer DVD holds 4.5 GB of data, while a CD holds a mere 700 MB..
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 drives are also capable of much higher data throughput than a CD drive. The average 52X CD-ROM drive reads data at 8MB a second, while a 24X DVD drive reads at 32MB a second.
DVDs are the most popular choice for movies and data storage these days but they are slowly being taken over by Blu-Ray. 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 additional related information on CDs and DVDs in relation to presentation and promotion check out the following website Packaging CDs and DVDs.
Even though both CD and DVD disks have the same media size and shape, the things they have in common end there. There are many different things between the two, such as what they hold and how much they can hold.
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.
Digital data is data that is stored as a series of ones and zeros. DVDs and CDs are digital data storage mediums so everything, including audio and video, is stored as ones and zeros. The pits and lands (where there are no pits) on the DVDs and CDs represent ones and zeros. The laser light will reflect off the lands but not off the pits when the disc is being read. The information from the laser is converted by a microprocessor into digital data that a computer can understand.
The tracks of a DVD are narrower as well, which allows for more tracks per disc and translates into more capacity than a CD. The typical single layer DVD holds 4.5 GB of data, while a CD holds a mere 700 MB..
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 drives are also capable of much higher data throughput than a CD drive. The average 52X CD-ROM drive reads data at 8MB a second, while a 24X DVD drive reads at 32MB a second.
DVDs are the most popular choice for movies and data storage these days but they are slowly being taken over by Blu-Ray. 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 additional related information on CDs and DVDs in relation to presentation and promotion check out the following website Packaging CDs and DVDs.
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