In data processing, a daemon is a background process that handles tasks without direct user input. Print daemons spool documents to print, HTTP daemons return data to the web browser issuing the request, task scheduling daemons trigger tasks when the clock triggers them, and so on.
These daemons derive their name in a roundabout way from Greek mythology. In the 1
decided to name the background processes after Maxwell's demon "Demons" – an imaginary being from James Clerk Maxwell's 19th-century thought experiment, which was responsible for the sorting of molecules in Maxwell's theoretical chamber. For his part, Maxwell had called his little thought experimentator a demon to nod to the demons of Greek mythology – supernatural beings (helpers) who performed tasks for the gods.
Although the spelling of the demon returned to the more traditional daemon over the years, the term stuck. Just as the Greek demons perform quiet tasks in the background, the modern computer demons continue the tradition of quiet and invisible help.