Draught beer or draft beer is beer that is served via pressurized line or hand pump/beer engine from a holding tank, barrel, keg, or cask to the glass as opposed to being poured from a bottle or can.
Beer conditioning typically occurs after primary fermentation has completed, and the beer has been racked off the yeast and trub bed to a different vessel such as a secondary fermenter, barrel, keg, holding tank, cask, or bottle. The beer then conditions over time; the length of time typically depends on the style of beer, and the type of conditioning that is desired.
If you are brewing an American wheat or perhaps a dry hopped pale ale, where a very fresh taste or aroma may be desired, then you would want a minimal conditioning time. But if you are brewing a barrel aged stout or a Flanders red sour, you may need to allow the beer to condition for over a year depending on the conditioning environment and desired flavors.