Draught beer, also spelt draft, is beer served from a cask or keg rather than from a bottle or can. Draught beer served from a pressurised keg is also known as keg beer.
Until Joseph Bramah patented the beer engine in 1785, beer was served directly from the barrel and carried to the customer. The Old English ("carry; pull") developed into a series of related words including drag, draw, and draught. By the time Bramah's beer pumps became popular, the use of the term draught to refer to the acts of serving or drinking beer was well established and transferred easily to beer served via the hand pumps. In time, the word came to be restricted to only such beer. The usual spelling is now "draught" in the United Kingdom, Ireland, Australia, and New Zealand and more commonly "draft" in North America, although it can be spelt either way. Regardless of spelling, the word is pronounced /drɑːft/ or /dræft/ depending on the region the speaker is from.
Canned draught is beer served from a pressurised container featuring a widget.Smooth flow (also known as cream flow, nitrokeg, or smooth) is the name brewers give to draught beers pressurised with a partial nitrogen gas blend.