A hamburger (short: burger) is a sandwich consisting of one or more cooked patties of ground meat, usually beef, placed inside a sliced bread roll or bun. The patty may be pan fried, grilled, or flame broiled. Hamburgers are often served with cheese, lettuce, tomato, onion, pickles, bacon, or chiles; condiments such as ketchup, mayonnaise, mustard, relish, or "special sauce"; and are frequently placed on sesame seed buns. A hamburger topped with cheese is called a cheeseburger.
The term "burger" can also be applied to the meat patty on its own, especially in the United Kingdom, where the term "patty" is rarely used, or the term can even refer simply to ground beef. Since the term hamburger usually implies beef, for clarity "burger" may be prefixed with the type of meat or meat substitute used, as in beef burger, turkey burger, bison burger, or veggie burger.
Hamburgers are sold at fast-food restaurants, diners, and specialty and high-end restaurants (where burgers may sell for several times the cost of a fast-food burger, but may be one of the cheaper options on the menu). There are many international and regional The term hamburger originally derives from Hamburg, Germany's second-largest city. In German, Burg means "castle", "fortified settlement" or "fortified refuge" and is a widespread component of place names. The first element of the name is perhaps from Old High German hamma, referring to a bend in a river, or Middle High German hamme, referring to an enclosed area of pastureland. Hamburger in German is the demonym of Hamburg, similar to frankfurter and wiener, names for other meat-based foods and demonyms of the cities of Frankfurt and Vienna respectively.
The term "burger" eventually became a suffix back-formation that is associated with many different types of sandwiches, similar to a (ground meat) hamburger, but made of different meats such as buffalo in the buffalo burger, venison, kangaroo, turkey, elk, lamb or fish like salmon in the salmon burger, but even with meatless sandwiches as is the case of the veggie burger.There have been many claims about the origin of the hamburger, but the origins remain unclear. The popular book "The Art of Cookery made Plain and Easy" by Hannah Glasse included a recipe in 1758 as "Hamburgh sausage", which suggested to serve it "roasted with toasted bread under it". A similar snack was also popular in Hamburg by the name "Rundstück warm" ("bread roll warm") in 1869 or earlier, and supposedly eaten by many emigrants on their way to America, but may have contained roasted beefsteak rather than Frikadeller. Hamburg steak is reported to have been served between two pieces of bread on the Hamburg America Line, which began operations in 1847. Each of these may mark the invention of the Hamburger, and explain the name.
There is a reference to a "Hamburg steak" as early as 1884 in the Boston Journal.[OED, under "steak"] On July 5, 1896, the Chicago Daily Tribune made a highly specific claim regarding a "hamburger sandwich" in an article about a "Sandwich Car": "A distinguished favorite, only five cents, is Hamburger steak sandwich, the meat for which is kept ready in small patties and 'cooked while you wait' on the gasoline range."