The word webcast is derived from "web" and "broadcast". Its use has varied over the past decade by different types of organisation and as the nature of the medium came into public use.
The term webcasting was coined when webcast/streaming pioneers Mark Cuban (Audionet), Howard Gordon (Xing Technologies) and Peggy Miles (InterVox Communications) got together with a community of webcasters to pick a term to describe the technology of sending audio and video on the Net...that might make sense to people. The term netcasting was a consideration, but one of the early webcast community members owned a company called NetCast, so that term was not used, seeking a name that would not be branded to one company. Discussions were also conducted about the term with the National Association of Broadcasters for their books - Internet Age Broadcaster I and II, written by Peggy Miles and Dean Sakai.
The generally accepted use of the term webcast is the "transmission of linear audio or video content over the Internet".
A webcast uses streaming media technology to take a single content source and distribute it to many simultaneous listeners/viewers.
The largest "webcasters" include existing radio and TV stations who "simulcast" their output, as well as a multitude of Internet only "stations". The term webcasting is usually reserved for referring to non-interactive linear streams or live events.
Rights and licensing bodies offer specific "Webcasting licenses" to those wishing to carry out Internet broadcasting using copyright material.
Webcasting is also used extensively in the commercial sector for investor relations presentations (such as Annual General Meetings), in E-learning (to transmit seminars), and for related communications activities. However, webcasting does not bear much, if any, relationship to the idea of Web conferencing which is designed for many-to-many interaction.
The ability to webcast using cheap/accessible technology has allowed independent media to flourish. There are many notable independent shows that broadcast regularly online. Often produced by average citizens in their homes they cover many interests and topics; from the mundane to the bizarre. Webcasts relating to computers, technology, and news are particularly popular and many new shows are added regularly.