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

CFG file extension

Configuration File

Settings Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

CSR file extension

Certificate Signing Request File

Web Files

DEB file extension

Debian Software Package

Compressed Files

GZ file extension

Gnu Zipped Archive

Compressed Files

INI file extension

Windows Initialization File

Settings Files

M4A file extension

MPEG-4 Audio File

Audio Files

MID file extension

MIDI File

Audio Files

MP3 file extension

MP3 Audio File

Audio Files

RSS file extension

Rich Site Summary

Web Files

RTF file extension

Rich Text Format File

Text Files

SQL file extension

Structured Query Language Data File

Database Files

TIFF file extension

Tagged Image File Format

Raster Image Files

TMP file extension

Temporary File

Backup Files

XML file extension

XML File

Data Files