what is an networked hardrive and an external hardrive?

Question

which one is better were can i buy a cheap one?

Answer 1

An external hard drive is something that you can readily attach/detach to any PC or laptop, usually through the USB port but some through the faster e-SATA port. Its main advantage is portability. It is like a huge USB flash drive in terms of actual size and capacity.
A networked drive could be internal or external but has to be connected always to a PC that is in a network. Anybody who connects to the network may access the drive (depending on levels of network security).