We use computers every single day (even if we don’t want to – every single day). How often do you think about what happens when you press Save, or download something. So let’s talk about your computer files.
What are files on a computer?
Let’s start at the basic level – what are files?
So often we talk about documents and spreadsheets, but not that often about files.
What is the difference?
Documents and spreadsheets are specific types of information – i.e., text and numbers.
File(s) is the general or generic term for all of the different information that you create or store.
This doesn’t just mean the information that you save, but files are also the information that your device needs to run.
And if you’re wondering if this refers to Windows, nope- it’s all computer systems, Windows, Mac, Linux and your phone.
(You really don’t see the files that your phone uses to run, as they are really hidden in the background.)
I wouldn’t recommend that you do this, but you can see (for Windows and Mac) the files that runs your computer. However, I’m going to tell you exactly how to get there – it’s much better if you leave them alone. 😆
What are types of computer files?
You can split files into a number of different options.
At the top level, you can split files into two groups
- System Files – ones that your device uses to work and run the programs/apps you install
- User Files – these are the ones that you create and save that store information.
System Files
Briefly, these ones split down into two more categories
- Operating System – the software that stars when you switch on, otherwise known (to most people) as either Windows or MacOS.
- Program Files – these are the files that are saved when you install software on your computer. They are the ones that do the hard work as you’re clicking on commands.
As I said above, that’s as far as I’m going, as you *really, really* don’t want to mess with them. It can cause your computer (or specific software) to have a problem.
Seriously – don’t mess with any system file.
User Files
These are your files.
The ones that you create, save, or downloaded.
They contain the information that you need to work with, the information that you need or are just interested in.
To look at your files you the main option is through File Explorer (Windows) or Finder (Mac).


Let’s take a closer look at one way to categorise them.
Documents, Spreadsheets and the Rest
The simplest, and most used option is the type of program that is used to create, open or edit the file.
Warning: Mini Rant
One of the things that is a pet hate of mine is when people use the wrong word when explaining things to me. Usually before they ask the question.
Sorry, I can’t help it, having been in IT for almost 30 decades (I started young 😊) and being a computer person, I had to understand and use the right phrases.
So when someone says “all my documents”, and I’m seeing a mix of files, it’s technically wrong and kinda annoying.
Fortunately, I’m a professional, so I swallow my irritation, smile sweetly and answer their question.
~ end of mini rant ~
Is this really important?
If you’re talking to someone who can work out what you’re talking about, or understands you – then no, not really
However, if you’re googling, or today using AI which can be quite literal, this may result in wrong or incorrect answers/info.
So the answer is “it depends”.
What’s the correct use of these descriptions
Document – anything created using a word-processor (To learn about the most popular word-processors take a gander at this blog: What do I need to know about Word-Processors). Today this can actually mean anything from a single page document/letter, to a dissertation to a webpage, to a magazine.
Spreadsheet – (yep you guessed it) things created with a spreadsheet program (Spreadsheet program options: What do I need to know about Spreadsheets). As a general rule information focused on numbers, (rather than text), from simple spreadsheet, through to complex and automated sheets.
Presentation – not as unspecific as the others, because as a general rule you create presentations to share information with others (And there’s a blog for presentations as well – What do I need to know about Presentations). There’s still a number of options, for a straight up slides and a talk, to interactive slides, to an automated show.
How does a computer know which program to use?
That’s an interesting question.
And the answer is the File Extension.
What’s that?
When you save a file and give it a name, that’s the only information that’s displayed when you looking at it.
However, what you don’t seen (as it’s hidden) is the full stop and the characters after it.
Generally, there are 3 / 4 characters, that are associated with specific programs.
In Windows Explorer, it shows you the program icon (on the left), and on the right, the Type column gives you more information.

The actual ‘bit’ that allows the correct icon and the type to be completed is the extension. This is automatically added to the file when it’s saved.
Now there is the main extension, for each program, but there are also variations:
| Program | Extension |
| Word | docx, dotx, doc, dot |
| Excel | xlsx, xltx, xls |
| PowerPoint | pptx, ppsx, ppt, |
| Text | txt |
| Adobe | |
| Pages (Apple Mac) | pages |
| Numbers (Apple Mac) | numbers |
| Keynote (Apple Mac) | keynote |
| Images | png, jpg, jpeg, gif, bmp |
Curious how to see the file extensions, take a look at How To Display The Hidden File Extensions In Explorer (Windows) on my YouTube Channel.
Next Steps
Now we all understand that a document or spreadsheet is a specific type of file.
Note: You may have noticed that I haven’t mentioned ‘Google’, and that’s because they don’t have a version that’s saved on your computer. If you download, it will let you choose Microsoft Office or Open Office.
While a ‘file’ is the generic phrase used to describe all and any item saved within a computer.
It’s next time to think about how you organise (and find later) all of the text and images that you created to help you schedule all that email and social media.
Other Posts about Computer Files
What do you need to know about computer files? (current post)
Do you really need file organisation?
What’s so great about online file storage
Why sharing is better than attaching
Are you searching your files to save time?
Improve your results with these advanced search techniques
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Managing your files well is one of those things that makes everything else easier. This plain-English guide covers the essentials — how to organise, store, share, and search your files — so you spend less time hunting and more time actually getting things done.
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what are computer files, what are files on a computer, what are types of computer files







4 thoughts on “What do you need to know about computer files?”
Thank you for clarifying this. You made is very easy to understand. Looking forward to learning how to organize my texts and images.
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