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

BAT file extension

DOS Batch File

Executable Files

C file extension

C/C++ Source Code File

Developer Files

CBR file extension

Comic Book RAR Archive

Compressed Files

CRX file extension

Chrome Extension

Plugin Files

CUR file extension

Windows Cursor

System Files

DAT file extension

Data File

Data Files

GADGET file extension

Windows Gadget

Executable Files

ICO file extension

Icon File

System 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

SRT file extension

SubRip Subtitle File

Video Files

TAR file extension

Consolidated Unix File Archive

Data Files

VOB file extension

DVD Video Object File

Video Files

XLR file extension

Works Spreadsheet

Spreadsheet Files