File formats and extensions in Intro to Computing - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a file extension?

A file extension is the set of letters after the last dot in a file name. It tells the computer what type of file it is, like .txt for text files or .jpg for images.

beginner

Why do computers use file formats?

File formats organize data in a specific way so programs know how to open and read the file. For example, a .mp3 file stores music in a way music players understand.

beginner

Match the file extension to its type:<br>1. .pdf<br>2. .mp4<br>3. .docx<br>4. .png

1. PDF document<br>2. Video file<br>3. Word document<br>4. Image file (Portable Network Graphics)

intermediate

What happens if you change a file's extension incorrectly?

Changing a file's extension wrongly can confuse the computer. It might try to open the file with the wrong program, causing errors or the file not opening at all.

intermediate

Explain the difference between a file format and a file extension.

A file format is the way data is stored inside the file. The file extension is the label at the end of the file name that hints at the format. For example, .txt is the extension, and plain text is the format.

What does the file extension '.jpg' usually indicate?

A An image file

B A text document

C A video file

D A spreadsheet

The '.jpg' extension is commonly used for image files, especially photos.

Which file extension is commonly used for audio files?

A .exe

B .mp3

C .pdf

D .docx

'.mp3' is a popular file extension for audio files.

If you rename a '.txt' file to '.jpg', what is likely to happen?

A The file will open as an image but show gibberish or error

B The file will become a picture

C The file will delete itself

D Nothing will change

Changing the extension does not change the file content. The computer tries to open it as an image but fails.

Which of these is NOT a file extension?

A .exe

B .html

C .zip

D .folder

'.folder' is not a standard file extension; folders are directories, not files.

What does a PDF file format mainly store?

A Audio tracks

B Raw images

C Formatted documents

D Executable programs

PDF files store formatted documents that look the same on any device.

Describe what a file extension is and why it is important.

Think about the letters after the dot in a file name.

Explain the difference between changing a file's extension and changing its format.

Consider what happens if you rename a file without converting it.