Scheduled conferences can exist as either current conferences or archived conferences. Typically, scheduled conferences that have outstanding timelines (papers are still being accepted; registrations are still being taken; the conference itself is in progress) are considered 'current' conferences, although it is possible to override some settings and archive a conference prematurely.
The Conference Manager can set when a scheduled conference is archived from the Conference Timeline page located on the Conference Manager page.
Current and archived conferences are available from their respective top navigation bar links when viewing a hosted conference.