CD ROM stands for Compact Disc read only memory. This disc is a storage device. To read such a disc one needs a device called CD ROM Drives. All modern CD-ROM drives can play audio CDs as well as video CDs and other data standards when used with the right software. It follows a mechanism to read CD ROM. This drive may be connected to the computer via an IDE, such as (ATA), SCSI, S-ATA, Firewire, or USB interface or a proprietary interface. One of the well known Interface is the Panasonic CD Interface. These CD drives employ a near-infrared 780 nm laser diode. This laser beam is directed onto the disc via an opto-electronic tracking module, which then detects whether the beam has been reflected or scattered. Transferring of data from CD-ROM drive is measured by transfer rate which may vary with different CD drives. For an example, if a CD-ROM drive has the ability to read the disc at 8x speed spins and at 4000 rpm (compared to the 500 rpm maximum for 1x speed) then it is giving a transfer rate of 1.2 megabytes per second.