You compare the results of any fitness parameter to the general population or a specific population. Or to a standard for fitness/performance.. You should of course be looking for these answers on your own. If you don’t understand the answers you find, that would be when you would come to others for an explanation.
These terms relate to how the results of an assessment are presented. Criterion-referenced means the test relates to some sort of established unit of measure. DORA is criterion-referenced because it reports in grade level equivalent scores.
For example, Daniel is at 45th percentile for cardio-fitness. This means if you took 100 students and ranked them from top to bottom, Daniel would be 45 from the bottom. So higher is better. Average is 50. Most tests which are accountability tests are norm-referenced.