There are manifold definitions of BNC acronym, such as Bayonet Neill-Concelman by British National Connector
, Barrel Nut Connector, Bayonet Navy Connector, Bayonet Nipple Connector, British Naval Connector and Baby N Connector.

The connector spoken of in the introduction - a BNC (Bayonet-Neill Concelman) connector - is usually used in a wireless security camera system that makes use of RF ("radio frequency") to send images captured by the security cameras to monitors and recording equipment.

What Does The BNC Connectors Do?

The “BNC connector” is organized to process both the analog and the serial digital
inter-face video broadcast. The BNC connector is as well capable of audio interface managing transmissions.
Sizes That are Available with Bayonet Neill-Concelman Connectors

Typically, BNCs are produced with fifty and seventy-five ohm impedance capacity, with the fifty ohm impedance is just good for frequencies that are up to four Giga hertz and the seventy-five ohm impedance for up to two Giga Hertz.

Check with the installation professional as to what cabling and connectors he intends to use. Some money can be saved by going with RCA plugs, but for those who want to make sure their cameras continue to transmit because they won't suffer cable disconnection, BNC connectors may be the most appropriate choice.