Relative Deprivation
We all have people to whom we compare ourselves. Don't worry, it's natural. But relative deprivation is when you have the perception that you are worse off than these other people you compare yourself to. Having this feeling typically leads to frustration. For example, let's say you have a group of friends you study with (and you tend to compare yourself to them) and on a couple of exams they all do well and you do poorly, even though you all studied the same amount at the same times, etc. You may feel that you are worse off than them because they are doing better than you.