A broadcast network is a group of radio stations, television stations, or other electronic media outlets, that form an agreement to air, or broadcast, content from a centralized source.
Broadcasting is the distribution of audio or video content or other messages to a dispersed audience via any electronic mass communications medium, but typically one using the electromagnetic spectrum, in a one-to-many model.
A television station is a business, organisation or other enterprise, such as an amateur television operator, that transmits content over terrestrial television.
Electronic media are media that use electronics or electromechanical audience to access the content.
For example, PBS and BBC are TV networks that provide programming for local TV station affiliates to air using signals that can be picked up by the home television sets of local viewers.
A television network is a telecommunications network for distribution of television program content, whereby a central operation provides programming to many television stations or pay television providers.
Streaming media, Internet radio, and webcasting are sometimes considered forms of broadcasting despite the lack of broadcast stations; its practitioners may also be called "broadcasters" or even "broadcast networks".
A webcast is a media presentation distributed over the Internet using streaming media technology to distribute a single content source to many simultaneous listeners/viewers.
Streaming media is multimedia that is constantly received by and presented to an end-user while being delivered by a provider.