Building a Faraday* torch helps to understand how it is possible to produce electricity from a magnet, a copper coil and a movement. The same principle is used in most electricity plants.
Depending on the plant, the movement is produced by different means (for instance by transferring the strength of water or steam to turbines). In the case of the Faraday's torch, the movement is produced by our body which takes its energy from the food we eat.
This project uses an electric condenser that stocks for a while the electricity produced. It is an interesting solution as it avoids the use of batteries which are full of harmful chemicals and must be often replaced which is costly. The LED (light-emitting diode) used is also very energy efficient (doesn't waste too much energy to produce light).
*Michael Faraday (1791-1867) is a British physician and chemist, well known for his studies in the field of electromagnetism. He has discovered the principle of electromagnetic induction, namely the production of electricity created by the movement of a conductor (ex. copper wire) close to a magnetic field.