This document discusses wireless power transmission. It begins by defining wireless power transmission as the transmission of electrical energy from a power source to an electrical load without conductors. It then provides a brief history of wireless power transmission dating back to Nikola Tesla and discusses various technologies used for wireless charging such as magnetic induction, radio frequency, and optical charging. Examples of applications like charging mobile phones, electric cars, and laptops wirelessly are also provided. The document concludes by acknowledging that while wireless power transmission has advantages like being electrically safe and convenient, it still has drawbacks such as low efficiency and high costs that require further research.