CD-ROM & DVD-ROM

WHAT ARE THEY?
CD-ROM stands for Compact Disc-Read Only Memory whereas DVD-ROM stands for Digital Versatile Disk. Both are optical disk which contains audio or software data whose memory is read only. A CD-ROM drive/DVD-ROM drive or optical drive is the device used to read them.

They can store large amounts of data up to 1 GB, although the most common size is 650 MB. A single CD-ROM has the storage capacity of 700 floppy disks, enough memory to store about 300,000 text pages .

USES
Mostly used by manufacturers to store music files and software, computer games and reference software such as encyclopedia. DVD-ROM can be used to store movies and more sophisticated data as it has a larger storage capacity.

ADVANTAGES

• Small and portable
• Very cheap to produce
• Most computers can read CDs
• Quick access to data ( faster than magnetic tape)

DISADVANTAGES

• Fragile ( easy to scratch or snap )
• Smaller storage capacity than a hard drive
• Slower to access than hard disk