I don't understand buying movies on ITunes

[DrewDevil]

Disclaimer: I used to have an Ipod, but it died and I haven't replaced it. The one I had didn't have video capability.

Disclaimer #2: I know this post makes it clear I am an old, non-hip doofus who doesn't know anything. I can accept that.

When you buy a movie from Itunes, do you then watch it on that screen the size of a postage stamp?

Or do you watch it on your computer?

Is there any way to get it to play on your TV?

If not, why are people buying movies to watch on a teeny tiny screen? I don't get it.