Oral communication includes face-to-face communication, telephone calls, and intercom conversations. It has advantages like being direct, time-saving, and building relationships, but disadvantages like lacking formal records and potential for distortions. Business speeches aim to inform, advertise, or persuade audiences and should have clear introductions, bodies, and conclusions. Active listening involves hearing, understanding, and remembering messages. Meetings and interviews involve planned oral exchanges of information between groups of people.