A cron job is a Linux command for scheduling a task to be executed sometime in the future. This is normally used to schedule a job that is executed periodically - for example, to send out a notice every morning. Some scripts, such as Drupal, may require you to set up a cron job to perform certain functions.
For most cron jobs, there are three components present:
- The script that is to be called or executed.
- The command that executes the script on a reoccurring basis. This is typically set in the cPanel.
- The action or output of the script, which depends on what the script being called does. Frequently, scripts called as a cron job modify files or databases, however they can perform other tasks that do not modify data on the server, like sending out email notifications.
Most scripts that require the use of a cron job will give you specific instructions on what needs to be setup, frequently giving examples.