Cron jobs are planned tasks that can be added to your web hosting control panel. Most tasks associated with site and server administration are repetitive tasks that can be smoothly programmed and automated. Unfortunately, maximum people don't how to program automated tasks, so it can be frustrating when you have to perform the same menial tasks repeatedly.
Within the cron jobs section of your hosting control panel, you can schedule tasks very fast which is normally take away minutes of your day. Almost every routine web hosting task can be automated utilizing a simple one line command within the user-friendly cron job interface. You can even select custom intervals, dates and times for the task to be performed .
Cron job is use to executes some scripts/commands periodically.
The cron service (daemon) run in the background which constantly check the crontab file and /etc/cron.*/ directories.
If you want to use cron job then you need to check the status of the cron service(daemon), It need to be running.