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

APK file extension

Android Package File

Executable Files

BAT file extension

DOS Batch File

Executable Files

CER file extension

Internet Security Certificate

Web Files

DB file extension

Database File

Database Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

ICO file extension

Icon File

System Files

PS file extension

PostScript File

Vector Image Files

SH file extension

Bash Shell Script

Developer Files

SLN file extension

Visual Studio Solution File

Developer Files

SRT file extension

SubRip Subtitle File

Video Files

SYS file extension

Windows System File

System Files

TORRENT file extension

BitTorrent File

Misc Files

VB file extension

VBScript File

Executable Files

VCXPROJ file extension

Visual C++ Project

Developer Files

ZIP file extension

Zipped File

Compressed Files