This last purpose is often the main one showcased in the conclusionary part of a report.
Along with other key factors the conclusion should specifically detail the main benefits of the report, what was learned, and precisely connect it to the main purpose the experiment.
Sometimes the conclusion is not separate from the discussion, i.e.
you may be asked to give a combined "conclusion/discussion".
This is usually just a list of the sources you consulted for your discussion.
serves many purposes; providing the step by step details of a particular experiment, conducting relevant literature reviews, interpreting research findings, and properly communicating what was learned from working through a particular experiment or lab.
An experiment with many variables that stretches over a considerable amount of time may require more attention in all sections than a smaller lab experiment that maybe took 2-3 hrs for example.
Also a conclusion should match a paper in most respects; 'skimpy' or underdeveloped conclusions are discouraged.
Likewise a conclusion that goes back to the main objective or hypothesis provides some much needed closure to the assignment.
In scientific reports the conclusion generally stands alone at the end of a report but may also be coupled with the discussion section as well.