Linux command for deleting files after x number of days

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I have a question about the second argument in the command line. -name 'db*'

I want this cron job to delete only e.g. /home/user/backup-2.4.2009_18-11-01_user.tar.gz files

How does the argument -name 'db*' removed those tar.gz files? I'm asking because I'm a novice with Linux command not because I'm challenging your method.

Thanks.