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

AI file extension

Adobe Illustrator File

Vector Image Files

APK file extension

Android Package File

Executable Files

ASPX file extension

Active Server Page Extended File

Web Files

BIN file extension

Binary Disc Image

Disk Image Files

CPL file extension

Windows Control Panel Item

System Files

CSR file extension

Certificate Signing Request File

Web Files

CUE file extension

Cue Sheet File

Disk Image Files

DRV file extension

Device Driver

System Files

EPUB file extension

Open eBook File

eBook Files

ICO file extension

Icon File

System Files

JS file extension

JavaScript File

Web Files

LNK file extension

Windows File Shortcut

System Files

SH file extension

Bash Shell Script

Developer Files

SITX file extension

StuffIt X Archive

Compressed Files

ZIPX file extension

Extended Zip File

Compressed Files