The only difference between the portable external hard drive and the hard drive in your computer is that the latter is a permanent fixture that is inside the computer and the other can be connected to a laptop or a desk top using USB or a Firewire Data cord. Now many computer retailers sell drive enclosures for build a portable external hard drive using the hard drive from a retired computer. Many portable external hard drive which is networkable can be connected using an Ethernet cable so multiple users can share the same hard drive. These portable external hard drives are usually powered by the data cable but in case of large drives a external transformer with 110 volt Ac adapter is required.
The benefits of external portable hard drives are that these devices can be connected to the computer through a high speed interface cable and it works as an additional hard disk. Portable external hard disk provides huge space to store large data and this keeps the computer from being overloaded and provides more space to the actual functioning of the computer. Portable external hard drives come with a storage capacity between 80 GB to 1 terra byte which gives a large free space to store movies, photos, music and in fact one can store a whole virtual work station in an external hard drive. Another major benefit of having a portable external hard drive is that it allows people to take a back up of all their files that are stored in computer. This protects the data from being lost due to attack from virus through internet. When, working online one can even switch of the external hard drive.
These portable external hard drives are no bigger than a snack box. It can be carried in a lap top bag and it gives the user the freedom to share the data with others, protect data and transfer the data by just plugging on to another interface. They work on plug and play basics and can be connected using a USB or a Firewire cables which enables the user to use it both in a desk top or a laptop. It is an advantage to have an external hard drive in places where the multiple users share the same interface as one can store personal and sensitive data externally and protects the data from being misused.
It is very important to check different external hard disk that are available in the market as new versions come with additional protection features like finger print readers and many more.