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

PPS file extension

PowerPoint Slide Show

Data Files

ROM file extension

N64 Game ROM File

Game Files

XLR file extension

Works Spreadsheet

Spreadsheet Files

PSD file extension

Adobe Photoshop Document

Raster Image Files

CSV file extension

Comma Separated Values File

Data Files

TIF file extension

Tagged Image File

Raster Image Files

DAT file extension

Data File

Data Files

MDB file extension

Microsoft Access Database

Database Files

MPA file extension

MPEG-2 Audio File

Audio Files

PNG file extension

Portable Network Graphic

Raster Image Files

TEX file extension

LaTeX Source Document

Text Files

FLA file extension

Adobe Flash Animation

Developer Files

MSI file extension

Windows Installer Package

Misc Files

HQX file extension

BinHex 4.0 Encoded File

Encoded Files