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

7Z file extension

7-Zip Compressed File

Compressed Files

TIFF file extension

Tagged Image File Format

Raster Image Files

SLN file extension

Visual Studio Solution File

Developer Files

XCODEPROJ file extension

Xcode Project

Developer Files

INI file extension

Windows Initialization File

Settings Files

SQL file extension

Structured Query Language Data File

Database Files

OBJ file extension

Wavefront 3D Object File

3D Image Files

MPG file extension

MPEG Video File

Video Files

DEB file extension

Debian Software Package

Compressed Files

CFG file extension

Configuration File

Settings Files

PRF file extension

Outlook Profile File

Settings Files

CUR file extension

Windows Cursor

System Files

VCD file extension

Virtual CD

Disk Image Files

BAT file extension

DOS Batch File

Executable Files

GADGET file extension

Windows Gadget

Executable Files