The ten most common file name extensions are file extensions that are most commonly used by computer users. Here are the ten most common filename extensions (not necessarily in order):

1. .doc – This is the file extension for a file created by Microsoft Word, the most popular word processing software. The latest version of Microsoft Word is based on OOXML and has the .docx file name extension.

2. .jpg – This is the file name extension for the compressed graphic format standardized by JPEG (Joint Photographic Experts Group). Most of the digital images we see on the Internet and on computers are in JPEG format and have a .jpg file name extension. This file can be viewed in most image viewing and editing programs.

3. .exe – This is the extension for Windows or DOS executable programs. If a file has this extension, it is a program and runs when opened. Self-extracting archives also have this extension.

4. .htm or .html: The extension for the HTML web page. HTML stands for “Hypertext Markup Language,” the language used to write web pages. This very page that you are viewing now is a web page with a file name extension of .htm.

5. .mp3 – The file name extension for the compressed audio format developed by the Moving Pictures Experts Group. This audio format is very popular these days because its size is many times smaller than Wave or AIF file. This makes it easier for people to download music from the Internet. The disadvantage of .mp3 is that the sound quality is not as good as the Wave or AIF file.

6. .mpg – This is a video format standardized by the Moving Picture Experts Group (MPEG). This file can be played with Windows Media Player, Winamp, Roxio Easy Media Creator, Apple QuickTime Player, or VLC Media Player.

7. .zip – This is the extension for any file compressed using ZIP compression, a type of compression that allows each file in the archive to be compressed separately. Programs that can open .zip files include WinZip, PKZip, and the popular WinRar.

8. .pdf – This is the file extension of the document created by Adobe Acrobat or other PDF production programs. PDF stands for “Portable Document Format” and can contain images, text, forms, outlines, and links. PDF files are usually created from another file, such as a web page or a Word document.

9. .xls – This is the file name extension for the Microsoft Excel spreadsheet created with Microsoft Excel, the most popular spreadsheet program.

10. .msi – This is the extension File extensions used for misc files, files that contain information about a particular installer. This is used for Windows updates and other software installers.