Following on from last week Are you using the right language? let’s talk specifically about file types.
The first question to ask is: What are file types?
A file type is a name given to a specific kind of file….
The terms “file type” and “file format” are often used interchangeably. However, a file format technically describes the structure and content of a file.
Each file type has one or more corresponding file extensions.
File Type Definition by TechTerms.com
File types refer to a file that’s created by a specific program; for example word-processing files (Word or Apple’s Pages) or a graphic image created by Paint, Photoshop or something else.
Recognising files as being from a specific program
Each file type or program uses specific three or four letters at the end of the filename, known as the extension.
It’s interesting to note, as operating systems (Windows and Mac) became more graphical, the program icon replaced the extension on screen.
Today, we don’t see the extension at all, just the program icon next to the filename.
Display the File Extensions
There may be a time that you want to be able to see the extension, so here’s how:
Microsoft Windows
- Open File Explorer
- Click on the View tab, in the Ribbon.
- Tick the option File name extensions, in the Show/Hide group

You can see the extension displayed at the end of the filename, after the dot (.)

Apple MacOS
- Open Finder on your Mac.
- In the menu (at the top of the screen) choose Finder > Preferences
- Click Advanced section.
- Select or deselect “Show all filename extensions.”

Hide the File Extensions
Windows or Mac: Repeat the the steps (above), and uncheck the show option.
Popular File Types
A quick guide to some of the file types, that you will see in on your computer (Windows or MacOS).
Microsoft Office
Word, Excel, PowerPoint, OneNote have their own file types.
Note: Outlook does have an file type, but we don’t often save emails separately.
Apple iWork
Pages, Numbers and Keynote
Google Workspace
I’ve included it because it’s a popular suite of programs, however, they are saved into the cloud, not locally on a computer; they don’t have their own extension/file type.
Instead we share links with others. If you want to save them, then we use other popular options, including MS Office and OpenOffice.
Standard Documents
Plain text, Rich Text, Portable Document Format
Video and Audio
There are a number of options for video and audio, with compression options (the size of the file and the quality). The image associated with them are most often the program that will play this file.
Windows Media Player, QuickTime, VLC Media Player
What use is seeing the file type?
Different file extensions can be viewed and played by different programs, but seeing the file extension shows you the specific file type.
E.g. PDF files are read by specific programs (i.e. Adobe Reader) and also web browsers (i.e. Google Chrome and Microsoft Edge). A different program icon displayed next to the file is confusing, seeing the extension can tell you what type of file it actually is.
Quick Warning
While it can be useful to see the file types and their extensions, it’s important to note that you shouldn’t edit the extension. This can make the file unrecognisable and stop it playing/opening.
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