How do cameras transport visual information to a different location with just a couple of wires?
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The same way any other TV works.
I’ll use NTSC (American old analog) as an example, because it’s simple. An NTSC video signal is a series of lines. Each line is just the brightness of a meter as it sweeps across the line. When the meter reaches the end, it jumps down to the next line, and the source transmits a very strong pulse (called H-blank).
When the meter reaches the bottom of the screen, the next several lines are filled with “special” data. At minimum, this is just an easily detected pattern (called V-blank) that the receiver can use to jump back to the top.
Color (if supported at all) is transmitted, by adding an oscillating sine wave to the video signal. Technically two (one for red, and one for blue), each staggered a quarter-cycle apart. During each H-blank, a few cycles of solid red are transmitted, so a color receiver can remember its timing and tell the two color signals apart. A monochrome transmitter can omit color altogether, and a monochrome receiver can ignore color.
Importantly, the thing with these kinds of analog TV, is that they are just a stream of voltages over time. So they don’t care if they’re transmitted over the air, or a pair of wires. (You need a minimum 2, since electricity needs a return path.)
Digital is the same, except that instead of the light readings being exact voltages, they’re specific patterns of 1’s and 0’s.
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