Porter is a style of beer that was developed in London in the early 18th century. It is well-hopped and dark in appearance owing to the use of brown malt.
Porter became the first beer style brewed around the world, being produced in Ireland, North America, Sweden, and Russia by the end of the 18th century.
The history of stout and porter are intertwined. The name "stout", used for a dark beer, came about because strong porters were marketed as "stout porter", later being shortened to just stout. Guinness Extra Stout was originally called "Extra Superior Porter" and was not given the name "Extra Stout" until 1840. Today, the terms stout and porter are used by different breweries almost interchangeably to describe dark beers, and have more in common than in distinction.