Conference - Formal meetings, perhaps over several days, on a number of different topics & with a larger number of delegate attendees. Conferences are not necessarily academic, and cover many different topics, businesses & areas of interest. Usually theses meetings & presentations are shorter in length averaging 90 minutes to two hours in duration.
Congress – This is usually a gathering held once a year where a specific discipline is highlighted and where achievements & results in that specific field are presented. The delegates are leaders in the specific field & selected delegates are invited to give talks or presentations.
Symposium – Formal & at times a prestigious event where subject matter experts gather in an academic setting. Participants are experts in their fields & present or deliver their viewpoints and opinions on the topic of discussion. A symposium may be described as a small scale conference. There are the usually breakout or round table discussions on the chosen topic after the presentations.
Seminar – Academic or continuing professional development instruction, offered by educational institutions or by either business or professional organizations. Attendees are brought together for instruction, focusing on a particular subject or topic, and are required to actively participate. The Instructor is a subject matter expert & will present and discuss throughout the seminar by e.g. lecture, visual materials, interactive tools or equipment, demonstrations, breakout sessions. There will be reference materials for the participants to use during the seminar & as a reference for later.
Workshop – Also a seminar, however a larger portion of the seminar may include hands-on-practice, working in groups, and case study work. This gives attendees immediate hands-on application to concepts & ideas presented & helps with reinforcing instruction. Materials are usually also given.