Did you know that the surface of a computer screen is covered with millions and millions of little tiny lights? Each little light is called a “pixel”. Each pixel has an address, which can be used to identify it. The address is just a number.
The screen is designed and built such that each one of these pixels can light up in any color, made brighter or dimmer or can be turned off completely.
These pixels are so small that if only one of them on the whole screen was made bright yellow, and the rest were “black” or “off”, you might not even notice that one yellow pixel at first, just like the one yellow pixel in the black box below, only imagine if the black box filled your entire screen.
When you watch a video on the computer screen, every pixel on the screen is separately turning different colors and each one is getting brighter and dimmer in just the right pattern, very, very quickly. When you look at the screen, you don’t always notice all that’s going on; you just see a video.
Each pixel can display thousands of possible colors at any level of brightness from zero light (black) to full on white. There isn’t even a name for every one of those possible colors; names. Hundreds of names would not be enough, so every color gets a number. Every brightness gets a number too. If you want to turn any picture into data, all you have to do is divide the picture up into millions of pieces, work out the right color number, and brightness number for each pixel address, and put those numbers into a file
This is exactly what happens, in a small fraction of a second, when you take a picture on your phone. The picture is converted into a bunch of numbers for the address, color, and brightnesses of each pixel
A video or a movie is just made up of millions of pictures, one after another, displayed on the computer screen. A new picture is displayed many times every second.
A computer can store sound as data, and convert the data back into sound in a similar way.