Some of Moodle's functions happen at regular, timed schedules. The most visible example is the mailing out of notices to the subscribers of a forum stating that a new message has been posted. A script called cron.php periodically checks to see if new messages have been posted to any forum. If so, the script causes the notice to be emailed to the members of that forum.

The script cron.php must be triggered at regular intervals. You can set this interval. The mechanism that triggers the script is called a cron job. Directions for setting up the cron job are in the http://moodle.org/ installation guide.

Some web-hosting services allow you to set up cron jobs. If you're buying hosting services, look for a host that allows you to set a cron job to run every hour, or even every few minutes. Some hosting services allow you to run a cron job only once a day. This means that Moodle will perform those functions that depend on cron.php only once a day.

If you've been given space on...