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

UUE file extension

Uuencoded File

Encoded Files

SQL file extension

Structured Query Language Data File

Database Files

GAM file extension

Saved Game File

Game Files

PRF file extension

Outlook Profile File

Settings Files

ZIPX file extension

Extended Zip File

Compressed Files

ASPX file extension

Active Server Page Extended File

Web Files

DB file extension

Database File

Database Files

CUR file extension

Windows Cursor

System Files

7Z file extension

7-Zip Compressed File

Compressed Files

TAR file extension

Consolidated Unix File Archive

Data Files

DMG file extension

Mac OS X Disk Image

Disk Image Files

FON file extension

Generic Font File

Font Files

ZIP file extension

Zipped File

Compressed Files

WAV file extension

WAVE Audio File

Audio Files

AVI file extension

Audio Video Interleave File

Video Files