This is different from the Enable Features area.  Here you are temporarily removing a function from your Attendees.   Any function checked is available to them (assuming their Role permits it) - and they can access it when they register or are logged in.   Any function that is not checked is not available to them.   It IS still available to you as administrator to manage on their behalf.   

Note - if their Role does not permit it - then it is not available to you as administrator for people of that Role.   Unless you have an Administrator override for that particular function to give you added powers to act for your attendees.

Use this Permissions tab if you have different phases for your event.  For example - if you do not wish to make meeting requests available to the earliest registrants - then uncheck "Select Participants".   Then, when you are ready for them to be able to see that tab - click it on again.