Reader - Contributor difference in Sharepoint

Question

I basicall do not understand the privileges of a reader and a contributor. Whats the difference.

Any authenticated user(added to the list) is a reader or a contributor?

In a system engineer-manager scenario, who will be the reader and who the contributor

Answer 1

A reader has read only rights, a contributor usually have crud access (create, read, update and delete) but cannot administer settings.

Answer 2

Contribute and Read are default site roles in SharePoint

Read grants the rights to view list items\document, open list items\document, View versions of list items\document, View Pages, browser user info, view form pages, use client integration (open documents from directly from sharepoint), Create certain kinds of sites, and use remote apis.

Contribute grants all those rights plus: Edit list items\documents, add list items]\documents, edit their own user info, create Alerts, Update personal web parts, add/delete private web parts, browse directories, and manage personal views.

Neither of these permissions map directly to an engineer-manager scenario - rather I would say it would be better to model it as producer - consumer. If the manager only needs to consume what the engineer produces, the manager should have read, and the engineer contribute. If the engineer only reads what the manager produces you can reverse the relationship.