Wireless power transfer is the conveyance of electrical energy from a source to a load through a spatial medium, such as air or vacuum, without the use of physical wires or conductors. As an academic concept and research domain, it encompasses the study of various electromagnetic principles, technological implementations, and system architectures for achieving efficient, safe, and reliable energy transmission over varying distances, including investigations into inductive coupling, resonant energy transfer, and electromagnetic radiation methods, with the goal of enabling novel applications and overcoming the limitations of wired power distribution.