“First-person view (FPV), also known as remote-person view (RPV), or simply video piloting, is a method used to control a radio-controlled vehicle from the driver or pilot’s view point. Most commonly it is used to pilot a radio-controlled aircraft or other type of unmanned aerial vehicle (UAV).”
https://en.wikipedia.org/wiki/First-person_view_(radio_control)
FPV cameras are used for flying drones and therefore need to have transmitters that have a long reach, i.e. much more than the wifi reach of an action camera. FPV cameras are currently not normally very high resolution cameras (due to current limitations in the ability to transmit HD imagery, although this is changing), and so there is often a higher resolution camera also attached to record the footage.
The “visual transmitter” communicates from the FPV camera to the antenna, which transmits to a “visual receiver” on the goggles or the FPV monitor. https://www.getfpv.com/new-to-fpv
FPV monitors cost upward of £35 (for a 7” model on 50% sale at Gearbest), but most are from £100. An adaptor (~$20) can turn a tablet or smartphone into an FPV monitor.
Eachine ROTG01
A FPV monitor can be constructed from separate components – screen, receiver, and battery. https://youtu.be/nm0-lWEut3c
However, FPV monitors are just receivers, and not controllers – this means that the camera cannot be controlled remotely, unlike app controllers for action cameras.
FPV receivers can be connected to a DVR recorder so that the recording is not happening at the place of filming, but at the point of viewing. This negates the requirement to remotely control a camera.
https://youtu.be/HbV4tzO-Wy8
Eachine ProDVR Pro DVR Mini Video Audio Recorder