Millions of computer users are considering buying external storage device so that they can have a back up of their important information. This is a basic thing to do as you can never be sure when the computer’s hard drive will break down. There are basically two types of external hard drives – Portable external hard drives and flash drives. Each has their own advantages and disadvantage. If you like to carry all your files while traveling then a flash drive is recommended as they are small in size and can easily fit in your pocket. But portable hard drives provide more storage space and they are less expensive. To read portable external hard drive reviews go to Portable External Hard Drive Review.