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

EXE file extension

Windows Executable File

Executable Files

TXT file extension

Plain Text File

Text Files

UUE file extension

Uuencoded File

Encoded Files

PSD file extension

Adobe Photoshop Document

Raster Image Files

VB file extension

VBScript File

Executable Files

APK file extension

Android Package File

Executable Files

SDF file extension

Standard Data File

Data Files

TIFF file extension

Tagged Image File Format

Raster Image Files

DNG file extension

Digital Negative Image File

Camera Raw Files

RTF file extension

Rich Text Format File

Text Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

DOC file extension

Microsoft Word Document

Text Files

SWF file extension

Shockwave Flash Movie

Video Files

7Z file extension

7-Zip Compressed File

Compressed Files

BIN file extension

Binary Disc Image

Disk Image Files