For me is the way that we have(humans) to take control of the universe
Great Question Elias,
Unfortunately, here are probably about as many perspectives on the nature of Magick as there are students and practitioners. Starting with the conceptual view upon which you, personally, can acquire the clearest understanding, and progressively refining it, is probably the best course to follow.
That being said: I understand it as practice of intentional manipulation of spiritual energy toward facilitating a physical, emotional, or perceptional result; something that I am rather new to practicing, myself.
In attempting to present a framework for students, I have in the past, employed the analogy of a swimming pool in which all cognizant entities are immersed. While opening passive abilities, (empathy, clairsentience, etc.) is the process of developing awareness and understanding of the ripples and eddies sent out when any entity moves, Magick is the deliberate generation and directing of these currents.
Hope it helps,
For myself, the question is, do the entities we contact also learn and practise magick, and are more powerful than ourselves simply because of their thousands of years experience? (or rather, eternal experience as their planes and dimensions lack time)