Hydropower energy is one of the most suitable and efficient source of renewable energy which depends on more than century of experience for this issue. The power capacity and facility are two criteria required for the classification of hydropower plant. The first one consists of five technologies: dammed reservoir, run of river, pumped storage, in stream technology and new technology gravitational vortex.  The other one is classified according to power scale is Large, Small, Mini, Micro and Pico Hydropower. Nowadays most of rural areas in developed and developing countries use the hydropower plant for producing electricity, it is cheap and effective. This paper gives a review of hydropower technologies and turbines; it is focusing on the categories and performance of hydro power systems and the most suitable turbines which can be used.