If we consider one of the athletics disciplines we have the hop, skip and jump (as it used to be called and the action still follows that description). Watch the action; the athlete take a run up to the start board where s/he hops off from one foot, lands on the other foot then takes off for the final jump when s/he lands on both feet. There is little or no discernible difference between the time in the air for each one.
However, a jump is either up and down or an attempt to cover a horizontal distance. A leap is most likely an attempt to get somewhere, such as across a gorge, crevasse or other obstacle and may also be a leap out from a cliff down into water but not upwards. The hop is performed (jumping or leaping) taking off from one foot and landing on the other one.