British comedian Daniel Maier once said if you get a message inviting you to a webinar, it's probably just a friend drunk-texting from a winebar. Joking aside, a webinar is a serious educational tool: It's a Web-based seminar. As with an in-person seminar, the online audience can participate by asking questions of the speaker or speakers.
A webinar usually has three defining characteristics. It takes place over the Internet instead of or as well as being an in-person event. It has an educational and informative nature rather than being entertainment based, and it allows some degree of interactivity, such as participants asking questions and receiving answers, which distinguishes it from a webcast.
Some webinars consist of a live video feed of the presenter. Others, particularly those demonstrating software or an online system, may incorporate prerecorded video to illustrate the points the speaker is making. Depending on the format of the presentation, the speaker may receive and respond to spoken questions or take part in a text-based chat during or after the presentation. Some webinars may have a moderator, which is someone other than the presenter whose job is to read submitted questions and choose the best ones for the presenter to answer. Most small- to medium-sized organizations use an external service that specializes in running webinars, such as WebEx, GoToWebinar and AnyMeeting.