How are primary sources of energy different from the final sources?

Answer

Difference between primary sources of energy and final sources of enery:

Primary Sources of Energy	Final Sources of Energy
1. Primary sources of enery are those sources which are available to us as free gifts of nature.	1. Secondary sources of energy are those sources which are not available to use as free gifts of nature.
2. They do not need any transformation (change from one form to another) before they are used as source of energy.	2. They need transformation before they are used as source of energy.
3. Coal, petroleum, gas are primary sources of energy.	3. Electricity is a well-known example of final source of energy.