The top ten common filename extensions are extensions of files that are most commonly used by computer users. Here are the top ten (not necessarily in order) most common filename extensions:
1. .doc – this is the file extension for a file created by Microsoft Word, the most popular word processing software. The most recent version of Microsoft Word is OOXML-based and has the filename extension of .docx
2. .jpg – this is the filename extension for the compressed graphic format standardized by the JPEG (Joint Photographic Experts Group). Most digital images we see in the internet and in computers are in the JPEG format and has the filename extension of .jpg. This file can be viewed in most image viewing and editing software.
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 HTML web page. HTML stands for “Hyper-Text Markup Language”, the language used in writing web pages. This very page you are looking at now is a web page with a filename extension of .htm.
5. .mp3 – the filename extension for compressed audio format developed by the Moving Picture Experts Group. This audio format is very popular nowadays because its size is many times smaller than that of the Wave or AIF file. This makes it easy for people to download music from the internet. The downside of .mp3 is that the quality of sound is not as good as that of 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 using Windows Media Player, Winamp, Roxio Easy Media Creator, Apple QuickTime Player, or VLC Media Player.
7. .zip – this is the extension for any file that is compressed using the ZIP compression, a kind of compression which allows every 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 for the document created by Adobe Acrobat or other PDF producing programs. PDF stands for “Portable Document Format” and may contain images, texts, forms, outlines, and links. PDF files are usually created from another file, like a web page or a Word document.
9. .xls – this is the filename extension for 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.