A cron job is a command, which runs conveniently in the background over a pre-set period and it also executes a script in a website hosting account. There are no limitations regarding what the script can be - PHP, Bash, Perl, etcetera, what it can do, or what exactly the file extension should be. Some examples are supplying an everyday report which contains all the end user activity within a given website, creating a regular backup or deleting the files within a particular folder. These types of tasks and / or almost every other script can be executed on time periods selected by the user - each few minutes, hours or days, and even once a month as well as once a year based on the specific intent. Working with cron jobs to automate diverse aspects of managing a site saves a lot of time and efforts.