"Racking" is a process of moving the beer from the primary fermentation container to a second container, which will allow the clean beer to settle and finish. The motion of the beer flowing from the first container to the second will mix the liquid, giving free floating yeast cells a chance to convert any remaining fermentable sugars. If you are using a plastic "ale pale", one of the best ways to rack your beer is to use a siphon tube and hose that will siphon the beer off of the sediment, called "trub" <pronounced "troob">, that has settled to the bottom of the bucket. There may also be some floating foam, caused by flocculation (separation) of the yeast, some of which rises to the top of the beer. Your siphon can remove the clean beer from above the trub and leave the floating yeast behind in the primary. This method is optional but aids complete fermentation of the beer and allows for longer fermentation without the risk of the flocculated floating yeast falling back down into the beer and giving it an "off" flavor. It also removes the beer from the trub which could also potentially yield "off" flavors if the beer sits on it for too long. This method is especially useful when brewing lager beers which can require lengthy fermentation at cool temperatures, up to two months.