1. To extend external identity user sessions to last up to 7 days, select Session Times Out After, and select a timeout value from the dropdown list (beta).Extend the session length to make it easy for your customers and partners to stay in your community. This option applies only to the external identity license.
2. To prevent external identity users from being logged out when they close the browser, select Keep users logged in when they close the browser (beta).This setting lets external identity user sessions remain active until users log out of the community or when the session times out. If unselected, external identity users are logged out when they close their browser. This option applies only to the external identity license.
3. To add more security when external users log in, select Enable device activation. This option applies to all external user licenses: external identity and all community licenses.When selected, Salesforce requires external users to verify their identity when they log in from a different browser or device.