Wikipedia
Natural wine is wine made without chemical and minimum technological intervention in growing grapes and making them into wine. The term is used to distinguish such wine from organic wine and biodynamic wine because of differences in cellar practices. All natural wines are, however, farmed organically at a minimum and many growers are biodynamic in the vineyard as well.
Strictly speaking, natural wines are wines that are produced without adding or removing anything during winemaking, although some growers add tiny quantities of sulphites at bottling, so that strictly speaking their wines are not natural wines, but 'only' organic (and possibly biodynamic).
Organic wine is organic in the sense of having been produced from organically grown grapes, but may be subject to chemical and physical manipulation in the winemaking process.
Among the most influential personalities and ambassadors for natural wines is worth mentioning sommeliers like Pierre Jancou (La Crémerie, Le bistrot Racines, Vivant and Heimat) and Ewen Le Moigne (Saturne) from paris and Anders Frederik Steen (Relae and Manfreds) previous sommelier in Copenhagen, now winemaker in Ardèche