An electrostatic shield named after its inventor Michael Faraday. It is made by placing conductive material (often aluminum or copper) around some device and connecting that material to ground. The better the conductor (in other words, the less resistance it has) the better shield it will be. The braided wire around the conductor(s) in audio cable is an example of a Faraday Shield. They are also used in transformer designs (to prevent capacitance between the primary and secondary windings), and the most sensitive electronics on circuit boards, in which case they are often deployed as a hard aluminum cage around said components. It is also common to use this shielding technique around sensitive guitar electronics to reduce the guitar’s sensitivity to stray fields.