What is the importance of Managers and Contributors while making a submission

While drafting a submission, there is a step to add any Managers and Contributors, by default the submitter name is displayed in the Manager list, but I want to understand what is the importance of this fields? What exactly does Manager and Contributor mean? 
 

<strong>This is detailed in the&nbsp;<a href="https://www.ema.europa.eu/en/documents/regulatory-procedural-guideline/iris-guide-registration-rpis_en.pdf">IRIS guide to registration v2.3 (europa.eu)</a>, chapter 5.4.&nbsp;</strong>