What are the advantages and disadvantages of using Cronjobs versus watchdog tools for monitoring directories in PHP?

When monitoring directories in PHP, one can use Cronjobs or watchdog tools. Cronjobs are scheduled tasks that run at specific intervals, allowing for regular monitoring of directories. On the other hand, watchdog tools continuously monitor directories in real-time and can immediately detect any changes. Using Cronjobs:

// Set up a Cronjob to run a PHP script at regular intervals to monitor directories
// This example runs the script every hour
0 * * * * php /path/to/monitor_directories.php