Wind waves are the part of the sea the wind is making right now, where you are, and they are usually what decides whether a day is comfortable. They are generated by the local breeze rather than by a distant storm, which is what separates them from swell.
Because they are still being pushed by the wind that raised them, wind waves are short, steep and disorganized, with crests close together and faces that break easily. A boat meets them in quick succession instead of riding over them, so the same measured height is far harder work than a swell of equal size would be.
They also build and fade quickly. Wind waves develop within a short time of the breeze picking up, which is why an afternoon sea breeze can turn a glassy morning into an uncomfortable ride home, and they subside soon after the wind drops rather than persisting for days the way swell does. How big they get depends on the wind speed, how long it has blown, and the fetch it has to work over.
In practice most sea surfaces are a combination: swell from somewhere far away with wind waves layered on top. That mix is why forecasts that separate the two are more useful than a single total wave height. Check the wind and wave conditions on your route, and plan the return leg for the wind you expect later in the day rather than the one at the dock this morning.
