Wooden and faux-wood venetians look very similar on the wall, but they are made of different things and behave differently - so the right choice usually comes down to the room rather than the look.
The difference
A real wood venetian has slats of genuine timber (often basswood), prized for being light, strong and naturally warm. A faux-wood venetian has slats of PVC or a composite made to mimic painted or grained wood, heavier than real wood but far more resistant to moisture.
Moisture is the deciding factor
This is the main reason to choose one over the other. Real wood can warp, swell or discolour if it is exposed to steam and damp repeatedly, so it belongs in dry rooms - living rooms, bedrooms, studies. Faux-wood shrugs off moisture and wipes clean, which makes it the sensible choice for kitchens, bathrooms and anywhere humid. If the room gets steamy, faux-wood wins outright.
Weight, width and looks
Real wood is lighter, so it spans a wider window in a single blind and stacks more compactly when raised; a wide faux-wood blind can be heavy enough that it needs splitting into two on one headrail. On looks, real wood has a depth and grain that the best faux-woods approach but do not quite match, while faux-wood gives a flawless, uniform painted finish - often the better match for a crisp white scheme.
Cost
Faux-wood is the more affordable of the two, which adds to its appeal for kitchens and bathrooms and for dressing several windows. Real wood carries a premium for the genuine timber and the lighter, wider-spanning slats.
Which to choose
Choose faux-wood for kitchens, bathrooms, humid rooms, wide budgets and a perfect painted finish. Choose real wood for dry living rooms and bedrooms, very wide windows, and where the warmth and grain of genuine timber are worth paying for.