4) Role VS Profile

Profiles control:

• The objects the user can access/action
• The fields of the object the user can access/action
• The tabs the user can access/action
• The page layout that is assigned to the user
• The record types available to the user
• Profile is required field on User.

Role control:

Record level access can be controlled by Role. Depending on your sharing settings, roles can control the level of visibility that users have into your organization’s data. Users at any given role level can view, edit, and report on all data owned by or shared with users below them in the hierarchy, unless your organization’s sharing model for an object specifies otherwise.