What is the use of Profiles in Salesforce.com

Profiles help determine record privileges. Assuming the User can see the record, Profiles determine what the User can do, view or edit on that record. Profiles control other system privileges as well (mass email, export data, etc) . we have many types of permissions.

Custom App Settings

Tab settings for standard/custom obj – default off?

Administrative permissions

General User Permissions

Object Permissions for standard/custom obj              

Field level security for standard/custom obj

Record Type Settings

Enable Apex/VF files