A change of direction where the stern passes through the wind. The counterpart to a tack, where the bow turns through the wind.
The distinction beginners get stuck on: in a tack you turn upwind, passing through the wind direction; in a jibe you turn downwind. On a kite that means bearing away, building speed, steering the kite across twelve o'clock to the new side, and switching your feet during the turn — kite first, feet second. The most common mistake is releasing your edge too early, which lets the pull drag you over the front of the board. In sailing the jibe is the riskier manoeuvre because the boom can swing across uncontrolled, which is why it's announced and the mainsail actively controlled.