HOW COMPUTERS WORK
Processing
Once we have some data, we need to process it so that our computer can figure out what we’re asking it to do and how to execute those requests. The job of processing information is given to the central processing unit, or CPU.
The CPU controls all the different components between hardware and software. We can think of it as the “brain” of the computer! The CPU also holds the responsibility of establishing communication between hardware and software. For example, if we turn the dial on our speakers up, data about that interaction is sent to the CPU. The CPU then deciphers the information and sends instructions to the speaker about how to handle this task. If we want to run software on our computer, it is also up to the CPU to perform all the necessary operations.
That’s a lot of responsibility for one piece of hardware. With all the different software and processes available to us, how can the CPU take in information and execute the associated instructions so quickly? This is where computer memory comes in handy!
Memory
Our computers have a lot of information to process — where does all this data get stored? Computer memory refers to the system or device used to store computer-based data temporarily or permanently. The type of hardware we use to store data depends a lot on how long we need to hold on to that information.
Primary Memory
Not all memory needs to last forever. Sometimes we just need information temporarily. For example, if we want to order food, we only need to remember the restaurant’s phone number long enough for us to dial the number — then we can forget that information until the next time we order food.
This same idea applies to running software on our computers. When a command to run a program is sent to the CPU, the CPU retrieves data from Random Access Memory, or RAM, in order to access what instructions it needs to execute. Accessing data from RAM is significantly faster than accessing data from other memory systems.
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This type of data is also only stored temporarily; once we exit a program or turn off the computer, the data is lost. For example, if we exit a word-processing application before saving, anything we wrote in the document is gone.
Secondary Memory
If we upload 150 photos to our computer, the computer needs a space to permanently store the data associated with the images so that we could access the pictures anytime. This type of data would most likely be saved onto our computer’s hard drive.
Output
Once the CPU processes data and sends out instructions on how to handle it, output is produced! We can think of output as the computer fulfilling the command we gave it through an output device.
Examples of output devices include the following:
- Monitors
- Speakers
- Printers
For example, if we clicked a mouse to open a file, the output would be the monitor displaying the file’s content. If we turned the volume on our speakers up, the output would be the sound becoming louder.
Output is the final step in the process of our computer interaction.
Review
Great job reaching the end of this lesson. Let’s go over what we learned about how a computer works:
- Input is data we give to our computers
- Processing is comprised of the translation of input and the instructions given for output
- Memory is used to store either temporary or permanent information
- Output is the information that gets returned by the computer
Now that we have a basic overview of how a computer works, we’re ready to take a deeper dive into learning about the processes behind making a computer functional.
