What are file extensions?

In my many years of mentoring people in tech, I found that even people who have been developing websites and creating designs still struggle with the concept of file extensions. After reading this article, you will know what a file extension is and why it is important.

Before we go into explaining what an extension is, there are some concepts that we need to understand.

1. Applications/Apps
2. Files.

What is an application?

An application, or app, as it is commonly called, is a computer program or piece of software that helps you perform tasks on your devices. When I use the word devices here, I am referring to your smartphones, laptops, desktops, and other electronic devices.

These apps are designed to perform very specific tasks, like writing letters, taking pictures, doing calculations, etc.

When you perform these tasks on your computer, you may need to store the results for future use. For example, when you take a picture with your camera, you may want to share it or see the picture in the future. So this picture will be saved in a file.

When you create things on your computer, the computer converts what you create to binary (zero and ones). You don't need to worry about understanding binary to use a computer. I just wanted to mention that so you can get the idea. It is the conversion that turns what you create into something the computer can store, which is a file.

What is a file?

A file is a collection of data/information stored on your device. These could be a flash drive, a hard disk drive, a memory card, etc.

So when you take a photograph, type a letter and save it, record a song, or download a book from the internet, they are stored as files.?

To use these files or edit the content, you need an application. For editing, you will most likely need the exact application that created and saved the file. To open these files, you may need a different application. But what happens when there are so many files on your computer or device? How does the device know which application to use when opening a file? Well, that's where file extensions come into play.

When you save a file, you need to give it a name. Some applications will provide you with a name if you do not provide one. This file name is made up of 3 parts.?

1. The text or name that describes the file
2. A period (full stop)
3. The extension.

The extension is usually the suffix (end part) of the filename.

For example, I saved this file as "what is an extension.docx".

• The name is "what is an extension" and the extension is "docx".
• As you can see, the extension and the name are separated by a period (full stop).

Together, everything forms what is called the file name.

A file extension can enable us to do several things:

1. It helps the computer to identify which application is supposed to open a file. If an application doesn't exist to open that file, you will get an error message informing you of that.
2. It also helps us identify which application is supposed to open a file. In a case where a file cannot be opened, the extension will help you know which software to install so that you can gain access to the file.
3. Help us identify the file type. By looking at an extension, we can tell at a glance what type of file it is. For example, a picture, a music file, or a video.?
4. It can help us prevent the accidental corruption of a file. When you try to modify a file with the wrong application, you can corrupt the original contents of the file thereby making it useless.
5. Extensions can also help you filter your searches when looking for files on your computer. For example, you can set your search to find only files with the .pdf extension.

If you are using a Mac, or a Linux-based Operating System, your file extensions may be displayed automatically. However, for Windows, you need to disable the settings that hides the extensions for the files. The steps are below.

1. Open File Explorer (You can right-click on the Start button and select "File Explorer" or press the Windows key + E on your keyboard).
2. In the File Explorer window, click on the "View" tab at the top.
3. In the "Show/hide" section, check the box next to "File name extensions."

Alternatively, you can follow these steps:

1. Open the Start menu and click on the Settings icon (gear icon).
2. In the Settings window, click on "Appearance and Personalization."
3. In the "Appearance and Personalization" settings, click on "File Explorer Options."
4. In the File Explorer Options window, click on the "View" tab.
5. In the "Advanced settings" section, under the "Files and Folders" heading, uncheck the box next to "Hide extensions for known file types."
6. Click "OK" to apply the changes and close the window.

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