CD & DVD RW
CD-ROM (Compact Disc - Read Only Memory) drive. CD DVD-ROM discs look exactly like music CDs but contain computer data instead of music. The advantage of a CD-ROM is that it can hold a vast amount of data (equivalent to the storage capacity of over 450 memory sticks). The other big advantage of CD-ROMs is that they are interchangeable. This means that you can own a range of different CD DVD-ROMs and choose which one to insert into your CD DVD-ROM drive.
Typical CD DVD-ROM
after the CD DVD-ROM came:-
40x12x48
CD DVDRW Drive 
16x48 DVD Drive
A power private theater is no further away than your PC with this 16X
DVD-ROM drive. Whether you're viewing Hollywood hits or showing customers
sales videos, the Artec 16X DVD ROM drive's performance will take your
breath away. Whether you are upgrading or simply replacing, Ultima always
has the product that fits everyone's need.
DVD recordable
drives--became common in 2002. At that time they cost over £200
but could record considerably more data on one DVD disk than the CD recordable
drives thus enabling the recording of full length movies and very large
backups.