Where did the word sandwich come from?
The Earl of Sandwich, either he or one of his servants put together two pieces of bread and some meat for the Earl to eat while playing cards. I don't know if the Earl won the card game.
Yes, the word 'sandwich' (lower case s) is a common noun, a general word for a type of food made with a filling between slices of bread or in a roll; a word for a thing. The word 'Sandwich' (capital S) is a proper noun as the name of a town in the southeast of England; the name of a specific place. The word 'sandwich' is also a verb.