external or internal what the diffrence?

[smiley]

just wondering what the diffrence is between a external hardrive and a internal.

because i am looking to buy a portable hardrive to put programs on such as limewire and bitorrent the portable hardive i am looking at is the Western Digital WDXMS600TE (60gig).

So if i did happen to catch a virus of limewire then it would only affect the portable hard drive right? and not my operating systems hardrive.

thx for the help smiley

 

[smiley]

thx for replies
i just want the externel hardive, to put prorames on such as limewire and bitorrent than i can just plg the drive in on any ones computor and start downloading songs. Is that possible to put lmewire and such programs on a externl hardrive