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

MDB file extension

Microsoft Access Database

Database Files

XML file extension

XML File

Data Files

BIN file extension

Binary Disc Image

Disk Image Files

7Z file extension

7-Zip Compressed File

Compressed Files

PL file extension

Perl Script

Developer Files

TORRENT file extension

BitTorrent File

Misc Files

ISO file extension

Disc Image File

Disk Image Files

LOG file extension

Log File

Text Files

ACCDB file extension

Access 2007 Database File

Database Files

COM file extension

DOS Command File

Executable Files

PIF file extension

Program Information File

Executable Files

C file extension

C/C++ Source Code File

Developer Files

CFM file extension

ColdFusion Markup File

Web Files

M4V file extension

iTunes Video File

Video Files

PDF file extension

Portable Document Format File

Layout Files