Here you can control who sees your view, and when they can do so. By default, only you can see your View. You can add Public, Logged in Users and Friends by clicking the appropriate add button. You can also assign access to individual Groups or Users by using the search tool.
Access dates can be assigned, making your View available for a specified period such as a course year, a project, or even for one day. All dates are optional. If you add more than one rule which matches someone, only one of the rules has to match for the person to be allowed to access the View.
Example: Nigel is in the group "The Coolpeople's Club". If you allow him to access your View today, and allow The Coolpeople's Club to access your View tomorrow, he will be able to access the view on both days.