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

CPP file extension

C++ Source Code File

Developer Files

EPUB file extension

Open eBook File

eBook Files

FLV file extension

Flash Video File

Video Files

FNT file extension

Windows Font File

Font Files

H file extension

C/C++/Objective-C Header File

Developer Files

ICS file extension

iCalendar File

Misc Files

INI file extension

Windows Initialization File

Settings Files

ISO file extension

Disc Image File

Disk Image Files

MP4 file extension

MPEG-4 Video File

Video Files

PART file extension

Partially Downloaded File

Misc Files

PHP file extension

PHP Source Code File

Web Files

PL file extension

Perl Script

Developer Files

RM file extension

Real Media File

Video Files

RPM file extension

Red Hat Package Manager File

Compressed Files

UUE file extension

Uuencoded File

Encoded Files