How can faxes send letters and pictures?

Let's start with a simple example. Suppose we have a Go board in front of us with many black and white stones. You call a distant friend and explain how the black and white stones are arranged on the board in front of you. If you can explain to your friend over the phone exactly how the stones are lined up, you will have a board at your friend's house far away that is lined up the same way as the board in front of you.
The most accurate way to tell how the stones are arranged is to say, "The first stone from the top and the first stone to the left is white. The first stone from the top, second from the left is black. The first stone from the top, third from the left is black. This means to explain the location of each stone and then say whether the stone is white or black. If there are 100 stones on the board, you can say this 100 times.
If you see a simple drawing on the board in front of you using black and white stones, you can use this method to send the drawing to your friend's house.
If you have drawn the letter "A" on the board with many black and white stones, you can send the same letter "A" to your friend's house.
The fax machine does this work more precisely, more accurately, and faster than ever before.
The fax machine thinks of everything written on a sheet of paper as a collection of black dots, and tells the other fax machine where the dots are. The fax machine then receives the information and draws a black dot in the same place. Then, the fax machine receives the information and draws black dots in the same places, creating a similar image. This means that the fax has been sent to someone far away.
If you look closely at the letters on the fax, you will see that the letters and lines are really made up of a group of small black dots.









