Cron is a computer program that can be used to make a computer do tasks at specific time intervals. It is used in UNIX computer operating systems and operating systems that are similar to UNIX, like Linux.
Cron can be used to schedule most repetitive tasks. It is often used to automate tasks related to a computer or computer network's maintenance or administration, although it can be used for many other tasks like downloading files from the Internet and downloading email at specific times or dates.
Cron is set up by editing a file called a crontab (cron table). This file lists the specific tasks for the computer to run and when the tasks should be run.