Daemon

What Is a Daemon?

A Daemon is a program that operates in the background and waits for a specified event or condition to trigger it. A daemon (typically pronounced day-mon, but also spoken to rhyme like ‘diamond’) is a one-of-a-kind software. 

They are utility applications that monitor and maintain specific subsystems to ensure the proper operation of the operating system. For example, a printer daemon manages and monitors printing services. A network daemon, for example, checks and maintains network communications.

The Purpose of Daemons

Daemons carry out certain actions at predetermined periods or in reaction to specific occurrences. Each daemon is specifically built to keep an eye on its little portion of the system. Since a user does not directly control them, they are practically invisible but necessary. Daemons can appear enigmatic since they do the majority of their work in the background, making it difficult to recognize them and what they actually do. 

How To Catch a Glimpse of a Running Daemon on Your Machine

Check for a process that finishes with the letter d to identify a daemon. There are numerous methods for catching a glance of a running daemon. They are visible in process listings via ps, top, or htop. 

These are essential programs in their own right - they serve a distinct purpose - but the pstree command will better suit our subject if you want to see all of the daemons operating on your machine. The pstree command is an excellent little application that displays the processes that are currently operating on your system in a tree diagram.

Furthermore, a daemon is a procedure that runs in the background and is generally beyond the user's control. A daemon is stated to have no controlling terminal. A process is a program that is currently running. It can be either running, sleeping, or zombie at any given time (a process that has completed its task but is waiting for its parent process to accept the return value).