The instructions a computer can understand are very limited.

To make a computer do something complex, we need to break a complex task into small simple instructions which work together.

How many chickens are there in this image?

Counting the number of chickens is actually a complex task, one that is made of lots of smaller tasks. We don't look at the picture and just know the number, we actually have a process for counting. For a person, the process is something like:

• scan from left to right
• everytime we see a chicken
• increase the count by one in our mind

This process can be applied to an image with any number of chickens, as long as we can remember the count so far, we can count thousands of chickens.

It is a similar process for a computer.