01. Energy: The ability or capacity to do work is called energy.
2. Work: Work is said to be done on a body when, by applying force it attains some displacement is called work.
3. Force: It is the agency that changes or tried to change the state of rest or motion of the body is called force.
4. Fundamental quantity: The quantity which can't be resolved into more fundamental quantities and other quantities are derived from it are called fundamental quantities.
5. Derived quantities: Quantities which are expressed as some combination of fundamental quantities are called derived quantities.
