External hard drives seem to be all the rage these days. They offer you the same data storage space, if not more, than the internal hard drive in your PC, but also give you portability unlike ever before. As popular as they are, one might wonder just what exactly an external hard drive is, and why they cost more than internal hard drives of the same capacity.

1 TB external hard drive

An external hard drive is simply an internal hard drive in its own housing. I know because I spilled coffee on mine one time and had to crack the case open to clean everything out. Luckily, it wasn't damaged. I have an older Western Digital 80 gigabyte external hard drive that I use for file storage and data backup.

Hard drives need a power source and a means of sending information from the drive to the computer. That's pretty much it. Two cables and you're done. Inside a computer, the internal hard drive gets its power directly from the power supply, and it is connected to the rest of the PC by means of a cable that plugs into the motherboard. External hard drives include their own power source, and usually connect to our PC by way of USB. When you buy an external hard drive, you're paying extra for that housing, which includes a power source and connector.

In my Western Digital 1 TB external hard drive, it contains a regular 3.5'D hard drive with a plastic housing that includes a power connector and some kind of converter that goes from the hard drive's IDE connector to a USB connector that goes to my computer. I could actually remove the hard drive from the casing and stick it inside my PC, provided that I had an IDE cable to connect it to the motherboard.

In addition to buying an external hard drive that is ready to be plugged in and put to use, you can actually buy hard drive enclosures made for turning internal drives into external ones. Dollar for dollar, you end up spending about the same amount of money. If you had an older IDE style hard drive and your new computer only supported SATA drives, an external hard drive enclosure would be a great way to use your old drive on your new PC.

One thing to keep in mind about most external hard drives is that they are still just a regular hard drive inside, and therefore susceptible to damage from shock or spills. Don't be fooled into thinking that plastic case will do much to keep the drive from being damaged while moving around. External drives do make data transport between two or more machines a lot easier, but most of them are not meant to be carried around as often as a USB flash drive. I know of someone who recently lost several hundred gigabytes of data after his external drive died from being moved around too much.

1 TB external hard drive