Vodka is a distilled spirit designed to be neutral, often made from grains (wheat, rye), corn, potatoes, or even grapes, then distilled and filtered to reduce congeners. The base material can subtly affect texture: wheat often feels soft, rye can feel slightly peppery, potato can feel weightier/creamier, though filtration and distillation choices matter more than people expect.
Flavor is intentionally restrained, so vodka’s real impact in cocktails is mouthfeel, proof structure, and how cleanly it carries other flavors. Compared with gin, vodka won’t contribute botanicals; compared with white rum, it won't bring sugarcane notes.