A hamburger (or burger) consists of a cooked ground meat patty,
usually beef, placed in a sliced bun or between pieces of bread or
toast.
Salisbury steak is made of chopped beef which is shaped to
resemble a steak and usually served in brown sauce.
The Salisbury steak was invented by an American physician, Dr.
J. H. Salisbury (1823-1905), and the term "Salisbury steak" was in
use in the USA from 1897. It is popular in the United States, where
it is traditionally served with gravy and mashed potatoes or
noodles.