An external drive is easy to install. It is a convenient way to increase data storage without messing around with the innards or you computer.

For the conventional external hard disk there are 3 types of connections:

USB connection

This is the most common of all. Although transfer rates here are throttled, making it slower than internal drives, the advantage is that it is compatible with most desktop and laptop computers.

Also, unlike most other USB devices, external hard disks come with their own power adapter.

FireWire

Similar to the USB connection, FireWire is much faster at transferring data than the USB connection. FireWire, however, is not available in many computers and laptops.

External SATA

External SATA is rarer than the above connections. The advantage of external SATA drives is the transfer rate. It provides the same performance as an internal drive.

External SATA requires you to purchase an additional adapter for your drive to interface with you computer. This highlights the disadvantage of the external SATA drive, since even fewer system support external SATA.

Removable Hard Disk Enclosures.

If your one computer system is used by the whole family, you can try external drive enclosures ad you can swap and change hard disks. One advantage is that family members do not see the contents of you drive and vice versa.

Installation is easy. It just requires you to slot the enclosure into on of the existing cd bays and secure it with screws.

External drive enclosures also add additional protection for your drive from shock and have their own fans for heat dissipation.