Pseudo devices
Pseudo devices are not back by real hardware however offer virtual interfaces to the OS. They offer functionality that is useful for testing, debugging and interacting with the OS. Examples of some devices in linux are:
/dev/null: All written data here is discarded./dev/zero: Provided an infinite stream of zero-values when read./dev/random: Generates a cryptographically secure random data./dev/urandom: Generates non-blocking random data./dev/full: Simulates a full disk generating an error when getting written to.