Sparging
From BrewWiki
Sparging, also called lautering is a step at the end of the mashing process where hot water is run through the grain bed to extract a sweet liquid called wort. The wort is later boiled and fermented to produce beer. For details of the sparging process, see the Mashing article.
Editors Note - If someone wants to expand this into a proper article detailing the different types of sparging, we could remove the short sparging section from the Mashing page and add Sparging as a link on the main Processes portal.