What do “reductive” and “oxidative” mean in wine?

Winemaker Jens Windisch describes reduction and oxidation in wine from a winemaker’s perspective. Jens makes wine at Weingut Werther Windisch in the Rheinhessen and he makes Riesling, Sylvaner, Spatburgunder and Portugeiser. Jens sat down with Ask a Winemaker during a trip sponsored by Wines of Germany and this video was produced with support from that organization.