Let's take a closer look. File extensions are things like .png or .mp4 at the end of a file name. The file extension is not ...

However, this important element of the file name can easily be made visible, and it is one of the first things a user should do after installing Windows. See extension. Windows 7 1. Launch Explorer 2.

You can identify a file's format by its extension, which appears at the end of the file name, such as .doc for Word documents or .png for images (PNG stands for Portable Network Graphics).