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

ASP file extension

Active Server Page

Web Files

CER file extension

Internet Security Certificate

Web Files

LUA file extension

Lua Source File

Developer Files

MPA file extension

MPEG-2 Audio File

Audio Files

PDF file extension

Portable Document Format File

Layout Files

PIF file extension

Program Information File

Executable Files

PS file extension

PostScript File

Vector Image Files

PSD file extension

Adobe Photoshop Document

Raster Image Files

SH file extension

Bash Shell Script

Developer Files

SWF file extension

Shockwave Flash Movie

Video Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

UUE file extension

Uuencoded File

Encoded Files

VCD file extension

Virtual CD

Disk Image Files

VOB file extension

DVD Video Object File

Video Files

YUV file extension

YUV Encoded Image File

Raster Image Files