File extensions – definition and basic information


File extensions are the integral parts of the files that are on each computer. Often, when working on a computer, we encounter a wide range of files, such as docx, ppt, part, mp3 or rmvb. We realize that they are there – but we often do not know what they are for on our computer.

File extension, also known as the filename extension is a suffix added to the name of a computer file, usually consisting of a number of characters placed after the last dot in the filename, which gives us information about its coding. In other words a file extension is a file format. It allows the operating system (e.g. Windows) to recognize what program it should try to open the file.

In the table below you will find a random selection of popular file extensions.


File extension The full name of the file Category

AIF file extension

Audio Interchange File Format

Audio Files

APK file extension

Android Package File

Executable Files

BIN file extension

Binary Disc Image

Disk Image Files

DB file extension

Database File

Database Files

DEB file extension

Debian Software Package

Compressed Files

PDF file extension

Portable Document Format File

Layout Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

RPM file extension

Red Hat Package Manager File

Compressed Files

RSS file extension

Rich Site Summary

Web Files

TAR file extension

Consolidated Unix File Archive

Data Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

TIFF file extension

Tagged Image File Format

Raster Image Files

XLR file extension

Works Spreadsheet

Spreadsheet Files

XLS file extension

Excel Spreadsheet

Spreadsheet Files

3DS file extension

3D Studio Scene

3D Image Files