A cron job is a command, which works automatically in the background on a predefined period and it also runs a script inside a web hosting account. There won't be any restrictions in regard to what the script is - PHP, Bash, Perl, etc., what it could do, or what exactly the file extension should be. Some examples are mailing a day-to-day report which contains all of the client activity on a specific site, generating a regular backup or deleting the content within a certain folder. These types of tasks and / or some other script can be executed on time periods picked by the user - every couple of minutes, hours or days, and even every month or maybe annually depending on the particular goal. Working with cron jobs to improve diverse elements of administrating a website saves considerable time and efforts.