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

JAVA file extension

Java Source Code File

Developer Files

MPA file extension

MPEG-2 Audio File

Audio Files

TGA file extension

Targa Graphic

Raster Image Files

MP4 file extension

MPEG-4 Video File

Video Files

CPL file extension

Windows Control Panel Item

System Files

SITX file extension

StuffIt X Archive

Compressed Files

YUV file extension

YUV Encoded Image File

Raster Image Files

DAT file extension

Data File

Data Files

FNT file extension

Windows Font File

Font Files

JAR file extension

Java Archive File

Executable Files

XLR file extension

Works Spreadsheet

Spreadsheet Files

XLS file extension

Excel Spreadsheet

Spreadsheet Files

TORRENT file extension

BitTorrent File

Misc Files

JPG file extension

JPEG Image

Raster Image Files