Ahhh, Carlton Draught... ^_^ ...made from beer. Well, as a beermaker it's also a mystery to me how commercial breweries can put "draught beer" (off the tap) into bottles. I think the closest explanation is "a bottled beer that tastes as if it had come off the tap". Lager beer has a light body and bitter flavours, and depends on the type of yeast used (compared to ales). However, commercial breweries filter the beer after fermentation, then pump carbon dioxide into it when bottling. If you buy a keg, then the beer is flat and you need to gas it yourself. If you haven't tried Coopers yet, then I recommend you do so - they allow their beer to carbonate naturally in the bottle (as evidenced by the yeasty sediment at the bottom).

Draught beer is served from a cask or keg. You can't get it in a bottle, but you can get it in a pressurized can which is basically a mini keg. I don't know about China, but in the US you can pick up a keg of beer and rent a tap from a beer distributor. This is like a metal barrel for serving and storing draft beer. It is a lot of beer and not very cheap, so it only makes sense for a very big party. The process is different for draught beer than it is for lager, but the tangible and easily seen difference is the way that it is served.