What is the difference between Sandwich and Hamburger?

Don't laugh at me, I'm not a westerner. Last time, I ordered a single hamburger (not meal) at Checkers in America, the seller told me that's a sandwich, I'm so confused! I think sandwich is the longer one in Subway.

Hmm.... last time I checked, a hamburger (at least in Texas) was a 'form of sandwich' consisting of at least one patty of ground meat (beef, turkey, chicken, etc.) placed in between at least two round buns.

BUT... don't let waiters/waitresses tell you off...

Next time just say, "isn't that what I said?" and give the waiter/waitress an atittude.

Oh wait... don't do that... unless you want snot on your burger. Just know how it's titled on the menu. Whatever word they use on the menu should be okay to use when you order. If it say 'pickles' don't say 'vinagered cucumbers' or something like that. Is that 'vinagered cucumbers' even used?

Oh... got most of my answer from:
http://en.wikipedia.org/wiki/Hamburger

I always considered (personal opinion) that the thing that made it a burger was the meat was ground meat, and it was served on a bun of some type. But that's just me.

The difference is in the spelling and the layout of the meal
A burger uses a bun or round loaf of bread then a beef patty or whatever is put between with all the other junk they use
Next a sandwich is made from a loaf of bread that has been sliced into leaves or slices
On this is applied butter to seal the bread , then (as the yanks call it ) jelly or whatever -you NEVER put a patty on a sandwich - you can use cheese tomoto fried egg ,onion ,spice etc or as the British eat them at 1600hrs in the evening , just plain white bread , butter and cucumber - this goes so well with pink gin !

So that my dear is the difference , and so is education of the waiter and that is why he never knew what he was serving
Change your eating joint now !