@chemist
Forms are those which can convert into one another like kinetic into potential and potential into kinetic for example if one ball is at rest it have stored potential energy when a force applied on ball and it moves then it will move with energy that is kinetic energy so potential has been converted into kinetic energy whereas types of energy are solar,wind,water,geothermal etc sources are not types sources are basicaly of two types renewable those can b renewed naturally as air,water etc and non-renewable resources are those which once exhausted then cannot b renewed e.g coal,gas,petroleum,oil etc...as other members said

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If I seem to boast more than is becoming, my excuse is that I brag for humanity rather than for myself.