One of my favorite foods is hamburgers.  I could eat them everyday
Same, a hamburger, beefburger or burger is a sandwich technically.
The hamburger became popular in the US after they were in the 1904 World's Fair.
The patty may be pan fried  but I like mine flame broiled.
Either way is good.  I always had a soft spot for White Castle.  Time magazine actually named it the most influential burger of all time
Typically burgers are made with with cheese, lettuce, tomato, bacon, onion, pickles, or chiles; condiments such as mustard, mayonnaise. But I do not like mayo.
The world largest hamburger you can buy at a restaurant is 499 dollars and weighs 185 pounds
A burger topped with cheese is called a cheeseburger.
Yes, and a burger with bacon is a bacon burger.  
Yeah they now have tons of  international and regional variations of the hamburger