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

CAB file extension

Windows Cabinet File

System Files

CBR file extension

Comic Book RAR Archive

Compressed Files

COM file extension

DOS Command File

Executable Files

CRX file extension

Chrome Extension

Plugin 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

RM file extension

Real Media File

Video Files

RTF file extension

Rich Text Format File

Text Files

TAR file extension

Consolidated Unix File Archive

Data Files

TEX file extension

LaTeX Source Document

Text Files

VOB file extension

DVD Video Object File

Video Files

WPD file extension

WordPerfect Document

Text Files

3GP file extension

3GPP Multimedia File

Video Files