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

ACCDB file extension

Access 2007 Database File

Database Files

AI file extension

Adobe Illustrator File

Vector Image Files

AVI file extension

Audio Video Interleave File

Video Files

BIN file extension

Binary Disc Image

Disk Image Files

DAT file extension

Data File

Data Files

DOC# file extension

Microsoft Word Document

Text Files

GED file extension

GEDCOM Genealogy Data File

Data Files

GZ file extension

Gnu Zipped Archive

Compressed Files

JAVA file extension

Java Source Code File

Developer Files

MAX file extension

3ds Max Scene File

3D Image Files

MDB file extension

Microsoft Access Database

Database Files

PIF file extension

Program Information File

Executable Files

RTF file extension

Rich Text Format File

Text Files

WAV file extension

WAVE Audio File

Audio Files

WSF file extension

Windows Script File

Executable Files