Anamorphic Setting in Handbrake - I'm Confused!

[w6rlf]

I've been using Handbrake to convert my DVD movies I've recorded for my Ipod Touch. I notice an "anamorphic" setting: The choices are none, strict, loose, and custom. I've read the material in the Handbrake guide but am confused:

1. Can someone provide an "anamorphic for dummies" explanation of "anamorphic?"
2. Is there one setting I should generally use? If not, what determines my choice?

Thanks very much.

Paul

[w6rlf]

P.S. What choice should I make regarding "keep aspect ratio"? It seems to default to that if "anamorphic" choice is "none".