system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do my electric guitar's pickups, together with my amp, create their sound?
gpt
Magnets. In simplest terms, the magnets in the pickups “pick up” disturbances in the magnetic field surrounding it, the capacitors and other electronics turn it into an electronic signal that is pushed through the amp which “amplifies” the signal into the speaker and our ears.

In more complex terms

 The basic science behind pickup function is Faraday’s Law of Induction. It states that a changing magnetic field causes an electric field to be set up in a nearby wire, causing a current to flow if the wire is part of a closed circuit (a loop of wire for example).

Since Faraday’s Law tells us we need a changing magnetic field to make an electric current, how does the magnetic field from the static permanent magnets change? That’s where the string comes into play.

See, the string is made of nickel and steel (iron+carbon), materials that are ferromagnetic. That is, a magnet attracts guitar strings. When this ferromagnetic metal vibrates in the magnetic field of the pickup, that disturbs the field which also crosses through the coil. That changing magnetic field makes a current flow that tracks the vibration of the string, and we have a working pickup!