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

BIN file extension

Binary Disc Image

Disk Image Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

CSS file extension

Cascading Style Sheet

Web Files

DBF file extension

Database File

Database Files

DXF file extension

Drawing Exchange Format File

CAD Files

EXE file extension

Windows Executable File

Executable Files

GZ file extension

Gnu Zipped Archive

Compressed Files

JAR file extension

Java Archive File

Executable Files

MAX file extension

3ds Max Scene File

3D Image Files

MPA file extension

MPEG-2 Audio File

Audio Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

PPS file extension

PowerPoint Slide Show

Data Files

PRF file extension

Outlook Profile File

Settings Files

SH file extension

Bash Shell Script

Developer Files

SWF file extension

Shockwave Flash Movie

Video Files