How much do you know about CD/DVD drives? Get a glimpse of the common facts -

CD stands for Compact Disc. It is a popular digital media for data storage. There are a variety of CD formats and the most commonly used are CD Recordable (CD-R), CD Re-Writable (CD-RW), and CD Read-Only Memory (CD-ROM).

Some basics about CD-R and CD-RW:

CD-R discs are write-one, while CD-RW discs can be written many times;
A CD-R recorder can only write to CD-R discs, while a CD-RW recorder can write to both CD-RW and CD-R discs;
Although CD-RWs can be written many times, the number of times a CD-RW disc can be re-written is limited;
CD-RWs are generally more expensive than CD-Rs;
CD-R and CD-RW discs come in standard 12 cm and 8 cm with the 12 cm type most popular;
The storage capacity of a CD-R or CD-RW disc depends on its specification. There are 21-minute, 74-minute, 80-minute, 90-minute, and 90-minute CD-R or CD-RW discs and their respective capacities are 184MB, 650MB, 700MB, 790MB, and 870MB.

CD-ROMs are commonly used as digital memory media for computers. Some basics about CD-ROM:

CD-ROM is a read-only media and can't be written;
CD-ROM is most commonly used in computer software distribution;
CD-ROM's physical dimension is 12 cm;
The storage capacity of a typical CD-ROM is 747 MB;
Computer CD-ROM drives read data from CD-ROM discs, yet they aren't as good at reading CD-R and CD-RW discs.

DVD is normally referred to as Digital Versatile Disc. As a popular video and data storage media, DVD comes with different formats. The base DVD format is DVD-ROM, which stands for DVD Read-Only Memory and on which any form of digital data can be stored.

The write-once recordable DVD comes with two competing formats: DVD+R is DVD-Recordable Plus and DVD-R is DVD-Recordable Minus. As they can be written only once, DVD+R and DVD-R discs are very popular in permanent data storage. However, due to the significant technical differences between the two formats, DVD+R and DVD-R discs have their own specific drivers to operate on them.

There are three competing rewritable DVD formats: DVD-RAM (DVD-Random Access Memory), DVD+RW (DVD Re-Writable Plus), and DVD-RW (DVD Re-Writable Minus). Since DVD-RAM allows random memory access, data can be written many times without erasing existing data as long as there is space. In addition, a specific portion of data can be deleted without affecting the rest of data. Although DVD-RAM is highly reliable, it is more expensive and less compatible than DVD+RW and DVD-RW.

Both DVD+RW and DVD-RW discs can be re-written more than 1,000 times. However, a DVD+RW disc can add or remove data without erasing the whole disc, while a DVD-RW disc must erase all existing data before writing new data to it.

The write-many-times characteristic of DVD+RW and DVD-RW discs makes them not suitable for permanent data backup and they are more expensive than DVD+R and DVD-R discs.

In general, DVD discs have much more capacity than CD discs. A single DVD disc can store up to 19 GB of data, while a single CD disc has a limit of about 750Mb in its capacity.

As CD and DVD are very different in their formats, a CD recorder can't be used to create DVDs. However, most DVD recorders work well with both DVD-Rs and CD-Rs.

Other CD/DVD Topics:

Back to Home

PC Fixer

Fix a wide variety of PC problems for Free!