The file always comes with the extension next to the file name such as .exe, .png . you can hide / show the extension of the file on your computer.
You can refer to the steps in the article below to hide / show the extension of the file.
Step 1: Open Windows Explorer -> Organize -> Folder and search options .
Or you can open the Start Menu , enter the Folder Options keyword and select Folder Options .
Step 2: In the Folder Options dialog box, click the View tab .
Step 3: In the View tab , in the Advanced settings section you find Hide extensions for known file types .
If you want to hide the extensions of the files you tick the box before Hide extensions for known file types , if you want to show the extensions of the files you unmarked in that box. After setup is complete you select OK .
Depending on your needs, you can hide or show the file extension. With just three simple steps on you can do it. Good luck!