They look like twins, but they're not. Kiteboards and wakeboards may share the same rectangular shape, but they are typically designed for different purposes.
The main difference between a kiteboard and a wakeboard is in the rocker. Because wakeboarders reach higher speeds than kiteboarders, their board's rocker is more pronounced to avoid dangerous wipeouts.
A kiteboarder is more worried about planing - too much speed is not usually a problem. It's even the opposite. Kiteboarders try to harness the power of the wind to gain as much speed as possible.
So, how does that translate into the shape of both boards? Traditionally, kiteboards feature one or two inches of rocker, while wakeboards display three inches of curvature. Kiteboards are also lighter (4-to-6 pounds) and more flexible than wakeboards (7-to-8 pounds).
Additionally, and unlike in wakeboards, kiteboards are often marketed with foot strap systems. Because it is considerably safer, and because kite tricks sometimes involve getting your feet off the board.
However, there are a few similarities between kiteboards and wakeboards. The core materials are basically the same, and the technology behind both models is identical. That is why there are many brands and companies producing boards for both sports.
Despite the resemblances, kiteboarders should never use a wakeboard in their riding sessions. Not even in high wind conditions. So, if you want to start kiteboarding, don't use your old wakeboard.
You will have many problems with the full boot bindings, the centered fins molded to the board, and your first upwind rides will feel awkward and more complicated.
Remember that the constant speed and pull of a boat are not comparable to the wind's gusty and shifty temperament and that wakeboarders often remove fins for hitting kickers, sliders, pipes, and other obstacles.