3. Pixels

Consider a very simple image such as the one below, that only has two colours - black and white.

This image can be divided up into a grid of smaller elements, as shown below

Each element in the grid is called a pixel. The more pixels used, the finer the details that can be represented.

As we mentioned earlier, computers can only handle and store 1s and 0s. Therefore let a single colour within each pixel be represented by binary 1 (say for white) and let a different colour (black perhaps) be represented by binary 0.

The image below shows each 1 bit pixel containing either binary 1 or binary 0.

Each row of pixels could be stored as a single binary number in memory. If the colour of a pixel needs to change, then the binary number itself is changed.