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

BAT file extension

DOS Batch File

Executable Files

CBR file extension

Comic Book RAR Archive

Compressed Files

CGI file extension

Common Gateway Interface Script

Executable Files

CUR file extension

Windows Cursor

System Files

DBF file extension

Database File

Database Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

DMP file extension

Windows Memory Dump

System Files

DXF file extension

Drawing Exchange Format File

CAD Files

FON file extension

Generic Font File

Font Files

MPA file extension

MPEG-2 Audio File

Audio Files

MSI file extension

Windows Installer Package

Misc Files

ODT file extension

OpenDocument Text Document

Text Files

ROM file extension

N64 Game ROM File

Game Files

SYS file extension

Windows System File

System Files

XLS file extension

Excel Spreadsheet

Spreadsheet Files