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

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

CUR file extension

Windows Cursor

System Files

EXE file extension

Windows Executable File

Executable Files

GZ file extension

Gnu Zipped Archive

Compressed Files

HQX file extension

BinHex 4.0 Encoded File

Encoded Files

KEYCHAIN file extension

Mac OS X Keychain File

Data Files

M4V file extension

iTunes Video File

Video Files

MP4 file extension

MPEG-4 Video File

Video Files

PIF file extension

Program Information File

Executable Files

RSS file extension

Rich Site Summary

Web Files

SQL file extension

Structured Query Language Data File

Database Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

TEX file extension

LaTeX Source Document

Text Files

VCD file extension

Virtual CD

Disk Image Files

3GP file extension

3GPP Multimedia File

Video Files