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

AIF file extension

Audio Interchange File Format

Audio Files

BAT file extension

DOS Batch File

Executable Files

BMP file extension

Bitmap Image File

Raster Image Files

CFM file extension

ColdFusion Markup File

Web Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

EPUB file extension

Open eBook File

eBook Files

FLV file extension

Flash Video File

Video Files

JAR file extension

Java Archive File

Executable Files

OTF file extension

OpenType Font

Font Files

PDB file extension

Program Database

Database Files

RTF file extension

Rich Text Format File

Text Files

TARGZ file extension

Compressed Tarball File

Compressed Files

VCD file extension

Virtual CD

Disk Image Files

VCXPROJ file extension

Visual C++ Project

Developer Files

WAV file extension

WAVE Audio File

Audio Files