International Relations scholars have always tried to define this term.

To me,the best one comes from Hans Morgenthau-know as the father of the realist theory in international relations.

He argues that'' power is the ability to control the minds and actions of others''.

For you?

Actually, it depends on the context;

Power (pour); noun

1. The ability or capacity to perform or act effectively.
2. A specific capacity, faculty, or aptitude. Often used in the plural: her powers of concentration.
3. Strength or force exerted or capable of being exerted; might.
4. The ability or official capacity to exercise control; authority.
5. A person, group, or nation having great influence or control over others: the western powers.
6. The might of a nation, political organization, or similar group.
7. Forcefulness; effectiveness: a novel of unusual power.

1. The energy or motive force by which a physical system or machine is operated: turbines turned by steam power; a sailing ship driven by wind power.
2. The capacity of a system or machine to operate: a vehicle that runs under its own power.
3. Electrical or mechanical energy, especially as used to assist or replace human energy.
4. Electricity supplied to a home, building, or community: a storm that cut off power to the whole region.
5. Physics. The rate at which work is done, expressed as the amount of work per unit time and commonly measured in units such as the watt and horsepower.
6. Electricity.
7. The product of applied potential difference and current in a direct-current circuit.
8. The product of the effective values of the voltage and current with the cosine of the phase angle between current and voltage in an alternating-current circuit.
9. Mathematics.
10. See exponent
11. The number of elements in a finite set.
12. Statistics. The probability of rejecting the null hypothesis where it is false.
13. A measure of the magnification of an optical instrument, such as a microscope or telescope.
14. powers Christianity. The sixth of the nine orders of angels in medieval angelology.
15. Archaic. An armed force.

power is to be able to command, even if people hate you or love you, if they still have to obey you that is power....

But to me personally, I think power is self improvement, whether the person or the individual, recognizing flaws and getting the vut above the competition.

I also think true power is when no one else knows the poser you wield.