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

CFG file extension

Configuration File

Settings Files

RPM file extension

Red Hat Package Manager File

Compressed Files

GAM file extension

Saved Game File

Game Files

XCODEPROJ file extension

Xcode Project

Developer Files

ICS file extension

iCalendar File

Misc Files

DXF file extension

Drawing Exchange Format File

CAD Files

7Z file extension

7-Zip Compressed File

Compressed Files

GED file extension

GEDCOM Genealogy Data File

Data Files

CSR file extension

Certificate Signing Request File

Web Files

ASF file extension

Advanced Systems Format File

Video Files

PL file extension

Perl Script

Developer Files

PDF file extension

Portable Document Format File

Layout Files

MSG file extension

Outlook Mail Message

Text Files

FNT file extension

Windows Font File

Font Files

ZIP file extension

Zipped File

Compressed Files