Might be worth explaining how moving images are drawn on a TV? For simplicity's sake, I'm assuming the TV is a black & white set, so no colors, just black, white, or shades of grey.
In old analog TV sets, the image is drawn by a moving beam of electrons, across the inside of the TV "screen", which is made of glass and coated with a layer of chemicals called phosphors. Where the beam strikes, the phosphors glow. If the beam is strong, the glow is bright white. If the beam is weaker, the phosphors glow a dimmer white, which we see as grey. If the beam is turned off, the phosphors don't glow, "making" black (because there's no other kind of light on the inside of the TV shining through to your eye).
If the beam stayed focused on one point, then you'd just have one point that was either black, grey, or white, depending on the strength of the beam. But the beam's focus can move from side to side, "painting" a line of black/grey/white across the glass.
If the beam could only move side to side, then you'd just have one line that was a mix of black, grey, or white along that line. But the beam's focus can also move up and down. The easiest way to make a picture with a beam that can move side-to-side and up & down, is by drawing a set of horizontal lines stacked on top of each other.
So, the entire "image" you see on an analog TV is made from stacked horizontal lines called "rasters". The lines are made by the beam painting one raster, shutting off, focus moving down a little and back to the other side, then turning on again and painting the next raster. This repeats until the beam has painted the last raster, whereupon it shuts off, focus moves back to the top for the first line, and the whole thing repeats.
(I'm purposefully ignoring something called "interleaving" that needlessly complicates the discussion at this level. Just pointing that out so no one who knows this stuff better than me chides me for ignoring it.
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The glowy phosphors fade fairly quickly, so each raster must be redrawn roughly (depending on what country the TV is made for) 30 times a second. Much less than that, and your eye sees unpleasant flicker in a moving image. Redraw all of the lines, and then repeat it, and the TV appears to always have an image on it. Making a "moving picture" on a TV is analogous to how flip-books work: You're seeing 30 complete images a second, one after the other, that to your eyes are a "moving picture".
The "what" of that moving picture -- what's it showing you? -- comes from a signal your analog TV is fed, either over-the-air from an antenna, or through a cable. That signal, like your analog TV, is also analog, meaning, it's not ones and zeroes, it's a signal that varies smoothly up & down (think of how music sounds, where it can be louder or quieter), with the "ups & downs" interpreted by the TV's electronics as, "make the beam this strong now, then less strong, then shut off and move down into position for starting the next raster, etc".
(It may help to think of the signal fed to your analog TV as something like what a player piano has -- the punched holes in a paper roll that tells the piano when to strike keys, and for how long, etc. It's a "program" of sorts.)
Analog signals are notoriously easy to add bumps & jogs to. This "noise" (what the OP called "static") is going to make the beam paint a different color than the original signal wanted, which is going to make random "speckles" on the moving image. Your eye is very good at noticing these.
Modern digital TVs and device screens work a fair bit differently. Most don't use phosphors, and their image is composed of thousands of little dots that can independently be turned on (white) or off (black) or levels in between (grey).
They also are fed a digital signal telling the TV what to show you -- i.e., what each of the little dots of the screen should be doing. "Static" in the sense of old analog TVs doesn't really happen, but it's possible to disrupt a digital signal. The results are usually a much more dramatic visual "hiccup" -- like, the picture breaks up into weird blocky shapes, or blacks out entirely.
Hope that made sense. If the OP is writing in modern times, then it doesn't (to me) make sense to talk about "static" on a digital TV.
