User Permissions and Access in salesforce
User permissions and access settings are specified in profiles and permission sets. To use them effectively, understand the differences between profiles and permission sets. User permissions and access settings specify what users can do within an organization: Permissions determine a user's ability to edit an object record, view the Setup menu, empty the organizational Recycle Bin, or reset a user's password. Access settings determine other functions, such as access to Apex classes, app visibility, and the hours when users can log in. Every user is assigned only one profile, but can also have multiple permission sets. When determining access for your users, use profiles to assign the minimum permissions and access settings for specific groups of users. Then use permission sets to grant more permissions as needed. This table shows the types of permissions and access settings that are specified in profiles and permission sets.