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

AI file extension

Adobe Illustrator File

Vector Image Files

AIF file extension

Audio Interchange File Format

Audio Files

ASF file extension

Advanced Systems Format File

Video Files

ASPX file extension

Active Server Page Extended File

Web Files

ASX file extension

Microsoft ASF Redirector File

Video Files

BIN file extension

Binary Disc Image

Disk Image Files

BMP file extension

Bitmap Image File

Raster Image Files

DOC file extension

Microsoft Word Document

Text Files

JPG file extension

JPEG Image

Raster Image Files

JSP file extension

Java Server Page

Web Files

MID file extension

MIDI File

Audio Files

PHP file extension

PHP Source Code File

Web Files

PS file extension

PostScript File

Vector Image Files

XLS file extension

Excel Spreadsheet

Spreadsheet Files

ZIP file extension

Zipped File

Compressed Files