What is the primary purpose of a file extension?

• A. Identify the program used to create or open the file
• B. Indicate the author's name
• C. Determine the file size
• D. Indicate the date of creation

Answer: (A)

File extensions serve as a hint about the file type so the system knows which program should open or handle it. The suffix after the last dot, like .txt, .jpg, or .docx, signals what kind of data is inside and how to interpret it. This is why the extension is linked to selecting the appropriate application to create, view, or edit the file.

Metadata such as the author's name, file size, or creation date describes attributes of the file but doesn’t tell the system which program should process it. Those details can be stored in the file's properties or within the file content, whereas the extension guides how the file should be read and handled.