A lot of viedoes on web site

Suppose I want to develop a web site with a lot of videos, since there will be a lot of videos I will need a lot of space in the server side, how can I store large amount of videos for the website?

I mean, for playing a video I need to write in the HTML tag a relative path, like: ~/MySite/Videos/video1.mp4, but since I will have a lot of videos I thougt to put all viedos on external usb's with a lot of space.

how can I tell the HTML to navigate to the usb drive, how to approach this issue?