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

BAT file extension

DOS Batch File

Executable Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

CSR file extension

Certificate Signing Request File

Web Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

FLA file extension

Adobe Flash Animation

Developer Files

FLV file extension

Flash Video File

Video Files

GZ file extension

Gnu Zipped Archive

Compressed Files

ODT file extension

OpenDocument Text Document

Text Files

PDB file extension

Program Database

Database Files

PHP file extension

PHP Source Code File

Web Files

PNG file extension

Portable Network Graphic

Raster Image Files

ROM file extension

N64 Game ROM File

Game Files

VCD file extension

Virtual CD

Disk Image Files

XHTML file extension

Extensible Hypertext Markup Language File

Web Files

ZIPX file extension

Extended Zip File

Compressed Files