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

CUR file extension

Windows Cursor

System Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

DOC file extension

Microsoft Word Document

Text Files

ISO file extension

Disc Image File

Disk Image Files

MPG file extension

MPEG Video File

Video Files

PDF file extension

Portable Document Format File

Layout Files

PL file extension

Perl Script

Developer Files

PPS file extension

PowerPoint Slide Show

Data Files

SAV file extension

Saved Game

Game Files

SH file extension

Bash Shell Script

Developer Files

TARGZ file extension

Compressed Tarball File

Compressed Files

TEX file extension

LaTeX Source Document

Text Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

WSF file extension

Windows Script File

Executable Files

XLS file extension

Excel Spreadsheet

Spreadsheet Files