KARDASHEV SCALE *as simple as possible*
Kardashev Scale is a scale made by a russian astrophysicist, Doctor of Physical and Mathematical Sciences, Nikolai S. Kardashev, which is a scale for measuring the civilization's level of advancement. It depends on how much energy a civilization currently harness' and uses. According to him, there are III(later scientists added more types of civilizations. Right now, the man kind is at 0.72(we are not even at the lowest). The formula is K=(log10P-6)/10 where P means the current consumption of energy in watts.
Type I(planetary civilization)- this is the stage for which we can most talk about, because we are only 100-200 years away from it. It is achieved when a civilization uses 10^17 watts. Type I civilization is able to convert into energy most of the particles from their native star that hit their planet. In our case: to convert into energy every photon that comes from the Sun. Not only that, the civilization will be able to harness the energy from the waves, volcanoes, wind, hurricanes, etc. Currently, we are using 10^13 watts. As I mentioned before, we are only 100-200 years away from Type I, we can see the changes right now: Internet, Europian Union( as trade centre), one official language(probably English, it's almost right now) AND IN MY OPINION ONLY: the Bitcoin, but we'll see how that goes.
Type II(solar civilization)- In this stage, a civilization consumes about 10^26 watts. It is when a civilization is capable of harnessing the energy from their native star. This can be done by building a Dyson sphere(this is a hypothetical galactic object that surrounds a star and collects most of its energy). By this point, the civilization will have colonised some other neighboring planets. Also, the civilization in this stage can probably control the orbit of their planet.
Type III(galactic civilization)- This era of human civilization will probably be using 10^37 watts. Here, a single person can use as much energy as today's small country. You shouldn't worry about how you could possibly do that, because this stage will be achieved in about few hundred-thousand years from now. This is where a civilization will be able to harness the energy from their entire galaxy(Milky Way in our case). Here not only they can move a planet from its orbit, but also to another solar system, merge solar systems themselves, absorbing energy from supernovas(a massive explosion when a star dies) and even maybe create a star.
Type IV(universal civilization)- This civilization can not be destroyed by any natural phenomenon known to current scientists. Can harness the energy of the whole universe.
Type V and VI are abstract civilizations where they can manipulate the time and space, maybe even living out of time and space, capable of creating and destroying universes. Such civilizations are almost impossible to imagine.