Permission sets

Permission sets are, as the term suggests, a collection of permissions or settings that give users access to specific platform features/functions.

Permission sets are used to extend application feature access to users without changing their profiles.

Every setting you can apply to permission sets is also found on profiles (but not vice versa). A given user is related to only one profile, but it can be assigned to multiple permission sets.
 
 Permission sets are not used to restrict permissions: you cannot use a permission set to revoke access to a specific object of a field if another permission set or user’s profile grants this permission.

Think about a service user who has a service profile (cloned from the standard user profile) and can access only accounts, contacts, and case objects. A selection of service users can also directly contact prospect customers using lead data: using a Lead Access permission set, you can give the service user access to read and write leads.

This concept is valid for whatever kind of permission that’s available on the permission sets.

You can create a permission set by going to Setup | Users | Permission Sets:

If you don’t fill in the License field, you won’t be able to see all the possible settings. Only use no license permission sets when you want to apply them to users whose license is allowed to enable it.

For example, don’t create a no license permission set with the Author Apex setting if you plan to assign it to a chatter-free user.

The permission set editor uses the enhanced profile view:

The Session Activation Required flag is used to create permissions sets that are associated with specific kinds of sessions.

Let’s say you have a mobile app that is capable of creating inventory custom objects (read, create, and edit). However, if the same user accesses the Salesforce application on their desktop, they should not be able to edit any inventory record; session activated permission sets can only be activated if the session has been created from that mobile app. For more information on this topic, please refer to the following Salesforce Help article: https://help.salesforce.com/articleView?id=perm_sets_session_map.htm.

The following limitations apply for the maximum number of permission sets that can be created in a given organization:

Personal edition	Contact manager	Group edition	Essentials edition	Professional edition	Enterprise edition	Unlimited and performance edition	Developer edition
N/A	1	5	10	1,000	1,000	1,000	1,000