"Racking off the lees" is a phrase you might hear when one is describing their winemaking process. To put it simply, after fermentation has occurred, it is when a winemaker siphons the wine away from (or "off" of) the sediment, into a new/clean container. This sediment is primarily comprised of grape seeds; stems; skins; pulp; and dead yeast (known as "lees", hence the term). One may also hear the term, "sur lies", which is French and translates to, "on the lees"; ie. this would be the opposite process.

"Unfined” means that the winemaker does not use any (fining) additives to his wine. A lot of winemakers use a fining agent (usually a protein such as that found in egg whites, milk, gelatin) to bind with something in the wine that they find objectionable. It binds and then falls to the bottom of the barrel (or tank), and allows the "clear" wine above to be racked off (again, think siphoning). This process is used in order to soften or reduce the astringency and/or bitterness of the wine, and to enhance clarity, color, taste and aroma.

“Filtering” is essentially the process using pressure to pass wine through some type of medium, in order to directly remove something undesirable to the winemaker. If a wine is said to be "unfiltered", then it means this process has not been used.