My cameras (Reolink) like all cameras out there are PTP (peer to peer), this means that the cameras are only activated when the application you use to view and control the camera is started and you make a camera selection. They don’t constantly stream unless you have the application running - I have many times forgotten I have my cameras running - this is a bad thing of you have limited data as I do.
If your cams and app support multiple displays you can view as many as the app supports. In my case I can view all 9 of my cameras at once.
One thing I do with my cams is to lower the bite rate and frame rate to the lowest I can so that the amount of data being sent doesn’t overwhelm my slower internet and set amount of data. Tonight I have pretty good speed for my internet (6.43mbps download, and 3.5bps upload), but this is still considered slow for this day and age.
For IR (infra red lighting for dark), there are basically 2 wavelengths in use: 850nm which is those red lights you see on cameras, and 940 which have no visible lights or n the camera, these would use for covert viewing in darkness.
This explains IR:
https://support.reolink.com/hc/en-us/articles/360011452574-Introduction-to-IR-Illumination/
Also with cameras there are various ways to power them and send the data for viewing.
PoE (power over Ethernet) in my opinion is by far the best way to power and view. The camera use one cable an Ethernet cable to both power and view the camera. There is never a lost signal, and only one cable to deal with which can run up to 330’.
WiFi cameras need a power cable to be run to the camera to power it. Data is sent to you router via wifi thus the camera cannot be too far from the router or go through to many walls.
Internet connection is another camera, this requires the camera to have a SIM card and a cellular data plan for the camera to function. These would be an option is you are too far from your router. This my least favourite type of camera.
If you are a far distance from your main router you would be better off using a wireless bridge such as I use to connect my barn office and all my cameras to the house where my router is.
This is also what I did for my nieces chicken coop, I put the wireless bridge receiver inside the coop with the camera (we ran a heavy gauge 100’ extension cable from the pool power supply outlet to the chicken coop for power), this all worked lovely but my sister was annoyed with having an Ethernet cable running to the wireless bridge transmitter at the house so we had to take the camera down.
Anyways I do not know if my chooks can see with the 85nm lighting or not, but for me it’s perfect for spying on them
Here is an article on chicken vision and what light they can see. They apparently cannot see the 850nm wavelength.
" The wavelength of visible light ranges from 400 nanometres (nm) to around 700 nm. Infrared light’s wavelength is longer than the light we can see, measuring above 700 nm. While humans can see in the range of 400–750 nm, chickens can see in the range of 315–750 nm. Additionally, chickens can see higher peaks at the spectrums of around 480 and 630 nm, said Rubinoff. "
https://www.thepoultrysite.com/articles/the-importance-of-lighting-in-poultry-production#:~:text=Infrared light's wavelength is longer,and 630 nm, said Rubinoff.