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

CGI file extension

Common Gateway Interface Script

Executable Files

3DS file extension

3D Studio Scene

3D Image Files

RTF file extension

Rich Text Format File

Text Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

AIF file extension

Audio Interchange File Format

Audio Files

ROM file extension

N64 Game ROM File

Game Files

3G2 file extension

3GPP2 Multimedia File

Video Files

CBR file extension

Comic Book RAR Archive

Compressed Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

PY file extension

Python Script

Developer Files

VB file extension

VBScript File

Executable Files

PAGES file extension

Pages Document

Text Files

7Z file extension

7-Zip Compressed File

Compressed Files

BIN file extension

Binary Disc Image

Disk Image Files

TGA file extension

Targa Graphic

Raster Image Files