An all-purpose knife like a chef’s knife can do a perfectly decent job slicing and chopping your produce, but a specialized vegetable knife like a nakiri has some special abilities.
Nakiri knives have flat, straight, rectangular blades, which makes them quite different from a chef’s knife or santoku. What the nakiri looks like, in fact, is a small cleaver, and that makes sense, because that’s essentially what it is. But unlike a cleaver, a nakiri is exceedingly thin and light, meaning it’s ideal for delicate work like thinly slicing fruits and vegetables.
The key difference with a nakiri knife is that the blade itself is flat, rather than curved. That means that you have to use it differently: instead of the rocking motion of a curved knife like a chef’s knife, you use an up-and-down chopping motion. One big benefit of this flat design is that you’ll fully separate each cut piece of food: no more slices of celery bound together by a little thread you didn’t quite cut through.
Because nakiri knives are specifically made for vegetable work, they have several adaptations to be as good as possible at that task. One of them is that many nakiri knives have some kind of protection against sticking. We’ve all been there: you’re slicing a cucumber, and the cucumber slices stick to the side of the knife, getting in the way or flying off at some inopportune time. Many nakiri knives have hollow indents in their sides, or are made using the elaborate Damascus method (which involves many precise folds of a single piece of steel, creating a beautiful wavy pattern). Those features reduce the tendency of sliced food to stick to the knife.