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

BIN file extension

Binary Disc Image

Disk Image Files

CFG file extension

Configuration File

Settings Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

DOC# file extension

Microsoft Word Document

Text Files

DRV file extension

Device Driver

System Files

FLV file extension

Flash Video File

Video Files

GPX file extension

GPS Exchange File

GIS Files

HTML file extension

Hypertext Markup Language File

Web Files

JAR file extension

Java Archive File

Executable Files

LOG file extension

Log File

Text Files

PDB file extension

Program Database

Database Files

SAV file extension

Saved Game

Game Files

SQL file extension

Structured Query Language Data File

Database Files

TTF file extension

TrueType Font

Font Files