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

PSD file extension

Adobe Photoshop Document

Raster Image Files

TGA file extension

Targa Graphic

Raster Image Files

RSS file extension

Rich Site Summary

Web Files

TIF file extension

Tagged Image File

Raster Image Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

SQL file extension

Structured Query Language Data File

Database Files

YUV file extension

YUV Encoded Image File

Raster Image Files

INI file extension

Windows Initialization File

Settings Files

PCT file extension

Picture File

Layout Files

ROM file extension

N64 Game ROM File

Game Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

ZIP file extension

Zipped File

Compressed Files

AZW file extension

Amazon Kindle eBook File

eBook Files

MP4 file extension

MPEG-4 Video File

Video Files

7Z file extension

7-Zip Compressed File

Compressed Files