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

BIN file extension

Binary Disc Image

Disk Image Files

CBR file extension

Comic Book RAR Archive

Compressed Files

CSR file extension

Certificate Signing Request File

Web Files

DMG file extension

Mac OS X Disk Image

Disk Image Files

FLA file extension

Adobe Flash Animation

Developer Files

H file extension

C/C++/Objective-C Header File

Developer Files

JAR file extension

Java Archive File

Executable Files

MDB file extension

Microsoft Access Database

Database Files

MOBI file extension

Mobipocket eBook

eBook Files

MP3 file extension

MP3 Audio File

Audio Files

RM file extension

Real Media File

Video Files

SYS file extension

Windows System File

System Files

TIF file extension

Tagged Image File

Raster Image Files

WAV file extension

WAVE Audio File

Audio Files