Most computers come with a small card installed that helps control all your disk drives. It is called the Drive Controller Card. (Wow, those computer scientists have some kind of imagination, huh?) You really don't need to worry about this device very much. There are two major kinds, IDE and SCSI. The only time you will ever care about this is when you buy a hard drive. Just know that the terms IDE and SCSI (pronounced 'scuzzie') are terms that describe the drive controller card.