Formal:
* Speech: This is the most general term for a formal address given to an audience.
* Lecture: This term implies a structured presentation of information, usually on a specific topic, often in an academic setting.
* Address: This word implies a formal, prepared speech, usually given on a special occasion.
* Presentation: This term is more general and can be used for both formal and informal talks, often involving visual aids.
* Keynote: This refers to a main speech given at a conference or event, often by a prominent speaker.
Informal:
* Talk: This is a more informal term for a speech, often given on a less formal occasion.
* Presentation: This term can be used informally, especially if the speaker uses visual aids.
* Discussion: This implies a more interactive exchange of ideas, where the audience participates in the conversation.
* Conversation: This term suggests a more casual and informal exchange of ideas.
Other terms:
* Public speaking: This is a general term for the act of speaking to an audience in public.
* Oratory: This term refers to the art of public speaking, emphasizing its eloquence and persuasiveness.
The best term to use depends on the specific situation and the nature of the speech.