explain about hoe the converting energy of hydroelectric power plant?

Answer 1

Basically, you build a large storage of water with an opening on the bottom (the dams, usually, but some times also natural lakes work nice).
When the storage is full, you open the opening, and water goes out with a very high speed (it is pushed by the tons of water over it).
You then make that water pass through a turbine which, pushed by the water, begins to turn at high speed.
The turbine is connected to a dynamo, which is a device that converts movement (cinetic energy) into electicity.
I saw little power plants whic did not use dams: they were mills where the turning wheel was connected to a dynamo.

Answer 2

Water lifted by evaporation & rainfall to high ground has potential energy.

this is converted to kinetic energy at it looses hight under the force of gravity.

this moving water generally passes through a turbine (other devices may be more suitable in specific circumstances) and some of the energy is converted to rotational force on the shaft.

the shaft is connected to an alternator ac, or dynamo dc, which turns windings or magnets to create elecro-motive force or voltage. connecting to a circuit and this produces a current.