cron system is a form of automation that puts something on a schedule. That "something" could be many different things. You can make your computer do what you want it to do just by editing a file. You don't even have to know where the file is kept and you don't have to keep track of it. You only have to type in a simple command, enter the "recipe" you want your computer to follow, and save your work. From then on, your computer will execute your instructions at the specified time until it is told to stop. Once you decide what you want to use cron for, the hardest part is remembering its syntax. (Repeat this mantra: minutes, hours, date, month, weekday.) However, with this cheat sheet nearby, you can declutter your mind and keep cron syntax conveniently close at hand.
Linux cron cheat sheet
Keep cron syntax close at hand with this cheat sheet.