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

APK file extension

Android Package File

Executable Files

APP file extension

Mac OS X Application

Executable Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

DEM file extension

Video Game Demo File

Game Files

FLV file extension

Flash Video File

Video Files

GED file extension

GEDCOM Genealogy Data File

Data Files

JAR file extension

Java Archive File

Executable Files

M file extension

Objective-C Implementation File

Developer Files

MIM file extension

Multi-Purpose Internet Mail Message File

Encoded Files

PL file extension

Perl Script

Developer Files

PSD file extension

Adobe Photoshop Document

Raster Image Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

RM file extension

Real Media File

Video Files

TEX file extension

LaTeX Source Document

Text Files

ZIP file extension

Zipped File

Compressed Files