The file monitor controls whether a file has or has not been changed. For example you control the modification date and if anybody has changed this file you are going to get informed by
e-mail or DirectMessage.
Otherwise you can control whether one of the file attribute (incl. size) has not changed for a specified period.
In addition you can execute a task if the file has or has not been changed, i.e. you can restore a previous version of a modified file if you did not authorize this modification.