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

BMP file extension

Bitmap Image File

Raster Image Files

CAB file extension

Windows Cabinet File

System Files

DBF file extension

Database File

Database 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

MOV file extension

Apple QuickTime Movie

Video Files

OTF file extension

OpenType Font

Font Files

PIF file extension

Program Information File

Executable Files

SQL file extension

Structured Query Language Data File

Database Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

TAR file extension

Consolidated Unix File Archive

Data Files

TGA file extension

Targa Graphic

Raster Image Files

XCODEPROJ file extension

Xcode Project

Developer Files