can anybody tell me if there is a difference between an ata hard drive and a IDE one. I bought a external usb case for an IDE hard drive but all I'm seeing is ata hard drives are they the same?
There's more specs than that involved but I don't know what they mean.
Maybe I should leave it to the pro's.
I want to have an external case that hooks up via usb 2 and that I can swap hard drives in.

Just be sure that the ATA is not ATA Serial because that would require a different type connector cable, not the ribbon type cable( flat cable) that has been used for many years. Chances are that your current hard drive is of the type that would require a ribbon cable. Below is an explanation of the IDE/ATA acronyms.

IDE (Integrated Drive Electronics) is a standard electronic interface used between a computer motherboard's data paths or bus and the computer's disk storage devices(a.k.a. hard drives). The IDE interface is based on the IBM PC Industry Standard Architecture (ISA) 16-bit bus standard, but it is also used in computers that use other bus standards. Most computers sold today use an enhanced version of IDE called Enhanced Integrated Drive Electronics (EIDE). In today's computers, the IDE controller is often built into the motherboard.

IDE was adopted as a standard by American National Standards Institute (ANSI) in November, 1990. The ANSI name for IDE is Advanced Technology Attachment (ATA). The IDE (ATA) standard is one of several related standards maintained by the T10 Committee.

the hard drive is an Ultra ATA/100 (parallel) interface
thanks for your help so quick.