Hello everyone- it is great to see you here posting regarding credibility, i

  
Hello everyone- it is great to see you here posting regarding credibility, impeachment and the right to discovery. We know that primary and secondary evidence exists in court. We also see that discovery is the request for documents for the defense and prosecution. Class-
If a defense attorney does not request certain items for trial are they entitled to get them? 
Is this different for the prosecution?
If I choose to bring my notes to court and the defense has not seen them, are they entitled to them if they do?
Why are the rules of discovery in place at all?