This is a command for scheduling jobs to be executed sometime in the future. A cron is normally used to schedule a job that is executed periodically - for example, to send out a notice every morning. It is also a daemon process, meaning that it runs continuously, waiting for specific events to occur.
Complete the form in order to add a job to the Crontab.
In case you would like to run a file which is in your account, you must use a path name in the following format (just substitute with your domain or subdomain name and the correct filename):
/home/www/subdomain.folder/file.name