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

CUR file extension

Windows Cursor

System Files

AI file extension

Adobe Illustrator File

Vector Image Files

GZ file extension

Gnu Zipped Archive

Compressed Files

CRX file extension

Chrome Extension

Plugin Files

CSR file extension

Certificate Signing Request File

Web Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

KMZ file extension

Google Earth Placemark File

GIS Files

SRT file extension

SubRip Subtitle File

Video Files

FNT file extension

Windows Font File

Font Files

ASX file extension

Microsoft ASF Redirector File

Video Files

M4V file extension

iTunes Video File

Video Files

7Z file extension

7-Zip Compressed File

Compressed Files

VCD file extension

Virtual CD

Disk Image Files