The difference between tech and magic is perspective. A commoner doesn't understand how a wizard conjures a fire elemental or constructs a tower out of thin air, so to them it's magic. The wizard does understand, to the wizard it's tech. A wizard's tower is a laboratory, it's where the wizard studies the physics of "the weave" (or other forces, depending on setting).
Even in this thread the answer to "what is magic in your setting" is "it's physics". Any sufficiently advanced technology is magic, and as a corollary, any sufficiently understood magic is science.