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

ACCDB file extension

Access 2007 Database File

Database Files

AI file extension

Adobe Illustrator File

Vector Image Files

BAT file extension

DOS Batch File

Executable Files

CSV file extension

Comma Separated Values File

Data Files

GAM file extension

Saved Game File

Game Files

GBR file extension

Gerber File

Data Files

HTM file extension

Hypertext Markup Language File

Web Files

IFF file extension

Interchange File Format

Audio Files

MP4 file extension

MPEG-4 Video File

Video Files

MSG file extension

Outlook Mail Message

Text Files

PPS file extension

PowerPoint Slide Show

Data Files

SH file extension

Bash Shell Script

Developer Files

TARGZ file extension

Compressed Tarball File

Compressed Files

VB file extension

VBScript File

Executable Files

XLSX file extension

Microsoft Excel Open XML Spreadsheet

Spreadsheet Files