Short for web-based seminar , a webinar is a presentation, lecture, workshop or seminar that is transmitted over the web using video conferencing software. Find out the difference between an online webinar and a video conference meeting and how to leverage a webinar to your advantage. WEBINAR definition : 1. an occasion when a group of people go on the internet at the same time to study and discuss…. Learn more. Find out what a Webinar is and how they work. Learn how to create an engaging webinar with extra tips and everything else you need to know.