IDE Hard Disk: Why Such a Name?
May 10th, 2010
Every hard disk is interfaced in the motherboard through a disk controller. This disk controller is the one that plays bridge between the hard disk and the operating system. For the user to access data from the hard disk, there is a data bus connecting the hard disk and the motherboard. The data bus is like a pipe where bytes of data are being transmitted. 
There are two kinds of data buses, Serial ATA and Parallel ATA, which are used in SATA hard disk and IDE hard disk respectively.
IDE is the abbreviation of Integrated Device Electronics. The Parallel ATA was earlier called IDE. That’s why hard disks that use Parallel ATA are called IDE hard disks.