Dwight Watt - Newspaper Article #112 7/27/2011

Question: What are file name extensions?


File name have two parts. The first part (before the last period) is a name you or a program has given the file to identify it so you can find it again. For instance I call the file this article is stored as newspaper-article-112-7-27-2011. Then I can find it in the future if I am looking for the article I wrote for 7-27-2011 newspapers. I could just as easily name it by the subject.

The file name extension is the past after the last period that the operating system (Windows) uses to know what program this file is associated with. You can name the extension also but that is only done in special situations.

The file this article is stored as has an extension of .doc That extension tells the operating system and us that the file is used in Microsoft Word. Other popular extensions are jpg or jpeg for pictures, xls for Microsoft Excel files, .htm for HTML files that make web pages, .sys for operating system files, .exe for program files that are run, and bunches more.

By default Windows hides common file extensions like .doc, .xls, .sys, .exe, and .jpg This can cause confusion as you can have two files with th same name which is not possible but the difference is the extension

If you would like to view all file extensions (my preference) open Computer and open the C drive. Then click Organize in Windows 7 or Tools in older Windows. Then choose Folder and Search Options or Folder Options. Then click the second tab View. Then uncheck Hide Extensions for Known File Types