External hard drive is a good option for individuals or small midsize businesses seeking an economical way of storing data / files.
Some companies also called "portable hard drive. It is portable in a sense, but I think you'd better not use it as portable because of the delicacy of the real hard drive in and the preciousness of your data. So when you buy a portable hard drive, make sure you understand the difference in size and weight between the hard disk portable external hard drive. Portable hard drive is only palm size and weight about 200 grams only, but an external hard drive is much larger and weighs about 2 kg.
External hard drive also comes with different interfaces: mainly, USB 2.0 and Firewire, as well as portable hard drive. The main difference lies in that the use of external hard drive 3.5 "portable hard drive then use the hard disk drive 2.5", hence the external hard drive is bigger, much heavier, but generally provided in large capacity, a 120 GB external hard drive is quite common.
The cost per GB of external hard drive is also much smaller than the laptop hard disk, so please do not be fooled by the cheap price of large-capacity "portable drive", it is actually external hard drive. Now the cost of 120 GB USB 2.0 hard drive cost about £ 190, amounting to only about 1.6 pounds / GB compare to those of tap backup products that cost at least £ 400, much cheaper and better too! Again Allcam external hard drive is again the best prices on the market.
As the capacity of external hard drive is usually high, so it is reasonable to have a discussion on the speed of data transfer. External hard drive with USB interface may not enough for those people who have a lot of data to date backup, so USB 2.0 or Firewire is the best choice. USB 2.0 has the advantage of being downward compatible with USB port, and a theoretical maximum speed of data transfer, in reality, the FireWire interface works even faster.