Types of Cable
It's called coaxial because it has two cores. In the picture on the left, you can see the outer braided wire surrounding the heavily sheathed inner core. The braided wire typically carries picture data while the inner core carries sound data.
In the home, co-axial cables are often connected using screw on type fittings. The use of crimp type connectors is much more prevalent where the connection may be outside and needs to be secure and possibly weatherproof.
There are two main types of crimp connections used:
The BNC (Bayonette Neill-Concelman) connector is a very common type of RF (Radio Frequency) connector used for terminating coaxial cable.
The BNC connector is used for RF signal connections, both for analogue and digital video signals (for example CCTV systems), amateur radio antenna connections, aviation electronics (avionics) and on nearly every piece of electronic test equipment manufactured in the last 35 years.
The TNC (Threaded Neill-Concelman) connector is a threaded version of the BNC connector.
It has better performance than the BNC connector at microwave frequencies. Invented in the late 1950s, the TNC connector has been employed in a wide range of radio and wired applications.