Separating wort from the spent grains (draff) after the completion of the mash by straining the wort then sparging (rinsing) the spent grains and hops. Found on http://www.lehighvalleyhomebrewers.org/glossary.html
Lautering is a brewing process where hot water (typically heated to 168-170 F) is used to flush the sugars from the crushed grains after the mash has completed. Once flushed from the grains, the hot water and sugars are then transferred from the mash tun or lauter tun. Found on http://www.westcoastbrewer.com/Beer_Glossary_and_Brewing_Terms.php