The term "webcast" derives from its original similarity to a radio or television broadcast. Early usage referred purely to transmission and consumption of streaming audio and video via the World Wide Web. Over time, webcast software vendors have added many of the same functional capabilities found in webinar software, blurring the distinction between the two terms. Webcasts are now likely to allow audience response to polls, text communication with presenters or other audience members, and other two-way communications that complement the consumption of the streamed audio/video content.
In 1992, InSoft Inc. launched Communique, a software-based Unix teleconferencing product for workstations that enabled video/audio/data conferencing. Communique supported as many as 10 users, and included revolutionary features such as application sharing, audio controls, text, graphics, and whiteboarding which allowed networked users to share and manipulate graphic objects and files using simple paint tools.
Using Webinar software participants can share audio, documents and applications with webinar attendees. This is useful when the webinar host is conducting a lecture or information session. While the presenter is speaking they can share desktop applications and documents. Today, many webinar services offer live streaming options or the ability to record your webinar and publish to YouTube and other service later.