A keyboard is a core component of every computer so it is important to understand whether a keyboard is an input or output device. Manufacturers have started adding feedback to keyboards which can muddy the water when understanding what type of device it is.
Keyboards are input devices because they send information to a computer’s processor rather than receiving it. Each time you press a key information is sent to the processor then converted into instructions the computer can understand. From there It is then sent on to various output devices.
Let’s take a close look at why keyboards are input devices and how the distinction is made between an input and output device.
What are input and output devices?
To understand why a keyboard is an output device it makes sense to consider the differences between the two. A computer is typically made up of four parts inputs, outputs, the processor, and the storage.
People often confuse the hard drive as an input or output device, but it is a storage device. The processor is considered the brain of the computer with the ability to send and receive data and make complex calculations.
Input and output devices are slightly different.
Input devices send information to the processor. A computer keyboard and mouse are good examples of input devices. A mouse tracks your movements and then sends this to the process, a microphone tracks your voice and then sends this data as an audio signal.
The thing every input device has in common is that its core purpose is to send data to the CPU, whereas output devices receive data.
Output devices receive information from the processor which they then decode and use to output something. A printer is an output device that receives data from the processor and turns it into a printed piece of paper. A computer monitor converts the data it receives into a visual output for you to understand what is happening on the computer.
The thing all output devices have in common is that their primary purpose is to receive data from the CPU and do something with it, whereas input devices send data to the processor.
Is a keyboard an input or output device?
A computer keyboard is an input device because it sends data to the computer processor rather than receiving it. Information flows to the processor in the form of keypresses and is then converted by the CPU into instructions the computer can use.
The computer system diagram below highlights the general flow of data through a computer. A keyboard is an input device because it sends data to the processor but doesn’t receive information back.
When you press a key down on the keyboard it is sent as an instruction to the processor which then converts it into a format the other components can understand. From there it is then sent to an output device like your computer monitor. If you are writing in a Microsoft Word document the computer will periodically send what you are writing to storage. So you don’t lose any progress. At a later date when you want to print the document the processor retrieves it from storage and then sends it to a different output device like a printer.
As you can see at no point does data flow back to the keyboard from the processor. That is why a keyboard is an input device and not an output device. Mechanical keyboards, like the Redragon K556, and tactile keyboards, like the Logitech G915, function in exactly the way I have outlined above.
Haptic keyboards are the type commonly found on your phone. These vibrate whenever you press a key down to mimic the same type of feedback you get from pressing a physical key on a normal keyboard. It’s easy to think these keyboards function as both input and output devices. But in reality, your phone’s CPU is receiving the keyboard data and then passing instructions onto the vibrating element in your phone, which is an output device.
Why is a keyboard not an output device?
A keyboard is not an output device because it only sends data to the CPU and doesn’t receive it. Output devices on the other hand receive data from the CPU rather than sending it.
So can a computer keyboard be used as an output device? Unfortunately not.
As you can see from the flow of data in the diagram above, a keyboard sends data to your computer every time you press down on a key. The computer then interprets this and sends instructions to other parts of the system. The computer never sends keystroke data or audio information back.
On the other hand, output devices like speakers receive information and then output it. Speakers receive audio files and output them as sound. A monitor receives information and then outputs it visually. The computer doesn’t receive data back from these devices which it then has to interpret and send on to other components in the system.
A keyboard is an input device because it sends information to your computer rather than receiving information from it. When you press a key down the information is then sent to your computer’s processor. It then distributes this to other parts of the system.
In contrast, output devices always receive information from the CPU. So if you are ever struggling to remember if a keyboard is an input or output device or any other component, just think about which way the data flows.