Quick question about external hard drive

[hungerdunger]

I want to get an external hard drive for my Bravia KDL40 EX65.

Browsing for suitable models I can see that some are powered through the USB cable while others have their own mains power supply.

Will both types work with my Bravia?  Does either type have any advantages over the other?

[Bravia55HX]

Hi,

A western digital my book essentials is highly recommended but any powered standalone HDD should be...

[hungerdunger]

Many thanks for your help.