The traditional device is known as a pie iron, pudgy pie iron, or jaffle iron. It consists of two hinged concave metal plates (either round or square) on long handles. The plates clamp together to form an enclosed compartment meant for cooking stuffed sandwiches. The plates seal the outside edges of the bread together, to completely enclose the filling (in theory, often not). They are typically made of cast iron to cook over coal or open flames. Stove top units are also available, made of aluminium and sometimes coated with a non-stick surface.
The electrical version is known by many names, including toasted sandwich maker, snackwich maker or jaffle maker in Australia and South Africa, toastie maker or toastie pie maker in the United Kingdom. They were invented by a Belgian company, and commercialised by John O'Brien of Breville in the 1970’s. The name Breville is still used to describe both a toasted, sealed sandwich, and the device used to cook them. Modern toastie makers are somewhat fickle things that have a tendency to spray hot cheese everywhere, brilliant :) .
Typical toasted sandwiches are a grilled cheese sandwich, tuna melt, or patty melt. Toasted sandwiches are also known by various names. They are frequently called toasties in Britain, brevilles, jaffles in Australia (also brevilles in South Africa), tosti in the Netherlands, or toasties in New Zealand. Sandwich toasters are less common in the United States where grilled cheese sandwiches are more popular. Although it must be admitted both current writers know very little about anything but good old british toasties.
Sandwich toasters are notorious for being used relatively little, because of their specialised nature. A survey carried out in 2005 suggested that 45% of British adults owned but did not use sandwich toasters. But they are possibly the most adaptable and useable machine of all.
However a more recent survey showed that 99.7% of the above was copy and pasted from a cheesey website trying to impress people in thier mid-life crisis.