What does multicast mean?
Multicast refers to sending the same data, audio, or video to several recipients at the same time, usually within a defined session or network group. A live conference, online lesson, or digital broadcast may use multicast so that all participating devices receive the signal simultaneously. Its defining feature is controlled group delivery: recipients receive a shared transmission without every unrelated device on the internet having to receive it. The word combines the prefix multi-, meaning “many,” with cast, as used in broadcast. It is especially common in discussions of internet protocol addressing, streaming media, teleconferencing, and communications infrastructure, where efficiency and selective reception are central concerns. Multicast is narrower than general broadcasting, which may reach an unrestricted public audience, and it differs from a simulcast, which distributes the same programme through several distinct channels or platforms.
A simultaneous transmission of data, audio, or video to multiple recipients connected to the same session or transmission group.
"The video stream was delivered as a multicast to participants at several offices."
Chiefly a telecommunications and computer-networking term.
To transmit data, audio, or video simultaneously to multiple recipients in the same session or transmission group.
"The server multicasts each presentation to every device in the lecture hall."
The third-person singular form is multicasts, and the simple past tense and past participle are multicasted.
Used for individual multicast transmissions or sessions.
"The network recorded two separate multicasts during the conference."
Multicast is live television with selective reception: everyone invited sees the same moment, without sending the entire stream to every device on the internet.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of multicast
Multicast is a compound formed from the combining form multi-, meaning “many,” and cast, as used in broadcast. The word developed in telecommunications terminology as a way of describing one transmission sent simultaneously to multiple participating recipients. Its formation reflects the established distinction between unicasting to one recipient, multicasting to a group, and broadcasting to a general audience.
Related word forms
How multicast is actually used
The term is chiefly used in telecommunications and computer networking. It differs from general broadcasting because recipients may belong to a defined group rather than receiving every transmission addressed to the wider public.
Easily confused with multicast
Broadcasting generally sends one signal to all receivers, whereas multicasting sends data only to recipients who have joined a particular transmission group.
A simulcast distributes the same programme over several separate channels or platforms, while a multicast delivers one transmission simultaneously to multiple session participants.