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

PNG file extension

Portable Network Graphic

Raster Image Files

PY file extension

Python Script

Developer Files

TMP file extension

Temporary File

Backup Files

EXE file extension

Windows Executable File

Executable Files

LOG file extension

Log File

Text Files

MPA file extension

MPEG-2 Audio File

Audio Files

3DS file extension

3D Studio Scene

3D Image Files

CSV file extension

Comma Separated Values File

Data Files

7Z file extension

7-Zip Compressed File

Compressed Files

FLV file extension

Flash Video File

Video Files

XLS file extension

Excel Spreadsheet

Spreadsheet Files

VCD file extension

Virtual CD

Disk Image Files

ASX file extension

Microsoft ASF Redirector File

Video Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

SLN file extension

Visual Studio Solution File

Developer Files