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Modern computers work by taking input, processing it, and returning it as output, millions of times per second.

How does it process this input?

All the input in the computer is sent to the central processing unit, or CPU3. The binary ones and zeros, or data, go through millions of tiny gates, each of which takes some inputs and returns an output.The CPU's gates also get data from the hard drive8 of the computer, which remembers information, the CD drive7, which is where you put disks for the computer to read, and other parts of the computer. Once the gates have processed all the data, the results are sent from the processor. Some of the results go to the outputs, while others go inside the computer to tell all the other parts of the computer what to do, like telling the hard drive to remember something.

 

Where does it get its input?

Different types of input come from different places. The keyboard10 sends letters and numbers to the computer, a mouse9 sends information on what to do with the cursor, and a microphone sends sounds. Although you don't control it directly, the internet can also send input. Even though all this information is different, it is all transmitted in the same language that all computers use, binary, which is just a series of ones and zeros.
 

What happens to the output?

The outputs of the computer are connected to external devices. The most important device is the screen1. The screen takes its inputs from the computer and understands the data as a picture. The screen then displays the picture on the screen. Another output device is the speakers. They take output from the computer and change it into sound. There is also output that you can't see or hear - for example when the computer sends data to the internet to ask for a web page.