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

7Z file extension

7-Zip Compressed File

Compressed Files

SITX file extension

StuffIt X Archive

Compressed Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

BMP file extension

Bitmap Image File

Raster Image Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

SLN file extension

Visual Studio Solution File

Developer Files

PL file extension

Perl Script

Developer Files

JPG file extension

JPEG Image

Raster Image Files

GBR file extension

Gerber File

Data Files

ISO file extension

Disc Image File

Disk Image Files

BIN file extension

Binary Disc Image

Disk Image Files

FLV file extension

Flash Video File

Video Files

UUE file extension

Uuencoded File

Encoded Files

MDB file extension

Microsoft Access Database

Database Files

GED file extension

GEDCOM Genealogy Data File

Data Files