Well, to know about cron and crontab, you can simple search this forum or use Google and search the net.
Cron is basically a chronograph that executes an executable file at a specific time or times.
Crontab is the table (file) that holds instructions for Cron.
Regarding cPanel, you will not find much help on
cPanel here. Most people here are UNIX/Linux jockeys who prefer not to use cPanel, and instead they manage their processes from the command line (shell).
That is why I gave you a link (below) to a tutorial on this. I think if you do a bit of homework (search and read) and then review the tutorial, you will be good to go. You can post back if you have specific issues/questions after you do some background reading.