[otrs] Need help organizing and prioritizing

My boss is wondering what the difference between escalated and reminder tickets are. Good question in my book, cause I neither know how to use them. For example, one queue is really saturated. Can we find a way to indicate to others that this person needs help and is (in turn) doing more work actually? I’ve read about escalated and reminder tickets but, how do I use them across the board? I would like a notification to go out if somebody is out of office and their tickets are going completely ignored.