A plenary session or plenum is a session of a conference or deliberative assembly in which all parties or members are present. Such a session may include a broad range of content, from keynotes to panel discussions, and is not necessarily related to a specific style of presentation or deliberation.
The term comes from the Latin word 'plenus' meaning 'gathered', and has come to be used in academic settings, such as conferences, just before, or after, breaking into smaller groups. This can be a time for summarising information, and may encourage class participation or networking.