Hydro power is electricity from hydro. By using the kinetic energy of the water, which is caused by the release of water from that height or flow of water, or up-down of waves to rotate the turbine.
Hydroelectric power is electricity generated by hydropower. The kinetic energy of water, which is caused by the release of water from the high water flow. Or more - to the waves. To spin turbines
Hydroelectric power is caused by hydropower. By using the kinetic energy of water, which caused the release of water from the higher or the flow of water or moving up and down wave, to rotate the waterwheel.