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

OTF file extension

OpenType Font

Font Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

TXT file extension

Plain Text File

Text Files

CSR file extension

Certificate Signing Request File

Web Files

VB file extension

VBScript File

Executable Files

GBR file extension

Gerber File

Data Files

GZ file extension

Gnu Zipped Archive

Compressed Files

LNK file extension

Windows File Shortcut

System Files

ODT file extension

OpenDocument Text Document

Text Files

TMP file extension

Temporary File

Backup Files

SYS file extension

Windows System File

System Files

PL file extension

Perl Script

Developer Files

MSI file extension

Windows Installer Package

Misc Files

7Z file extension

7-Zip Compressed File

Compressed Files

TOAST file extension

Toast Disc Image

Disk Image Files