Profile Vs Permission Sets Permissions and Access Settings?

1. User permissions and access settings specify what users can do within an organization.

2. Permissions and access settings are specified in user profiles and permission sets. Every user is assigned only one profile, but can also have multiple permission sets.

3. When determining access for your users, it’s a good idea to use profiles to assign the minimum permissions and access settings for specific groups of users, then use permission sets to grant additional permissions.

The following table shows the types of permissions and access settings that are specified in profiles and permission sets. Some profile settings aren’t included in permission sets.

Permission or Setting Type	In Profiles?	In Permission Sets?
Assigned apps	TRUE	TRUE
Tab settings	TRUE	TRUE
Record type assignments	TRUE
Page layout assignments	TRUE
Object permissions	TRUE	TRUE
Field permissions	TRUE	TRUE
User permissions (app and system)	TRUE	TRUE
Apex class access	TRUE	TRUE
Visualforce page access	TRUE	TRUE
Service provider access (if Salesforce is enabled as an identity provider)	TRUE	TRUE
Desktop client access	TRUE
Login hours	TRUE
Login IP ranges	TRUE

http://login.salesforce.com/help/doc/en/perm_sets_overview.htm