File extensions, a brief explanation

Since we started using computers we are aware of the existence of various types of files, we differentiate from each other according to the extension present; the extension is nothing more than a series of two or three characters placed after the file name, separated from this with one point. Essentially, all computer files have a specific extension, the extension allows the systems and software know what to do with a specific file while tells users what program should open these documents.

We use extensions daily but, we have to start to think what they mean; Below is a summary of the meaning of the extensions most commonly used today.

General System extensions

.COM ---> MS-DOS Application

.DAT ---> Data, database

.DB ---> Data Base (database)

.INI ---> Initial (initial setup files)

.TMP ---> Temporary (temporary files)

.TXT ---> Text (plain text files, unformatted)

Extensions for Office Documents 

.DOC, .DOCX,  ---> Document (Word documents)

.XLS ---> Excell Acronym

.EPS ---> Encapsulated Postscript

.PPT ---> Powerpoint

Extensions for Document Imaging

.JPG / .JPEG ---> Joint Photographic Experts Group

.GIF ---> Graphic Interchange Format

.PNG ---> Portable Net Graphics

Extensions for Audio Files

.MP3 ---> Short for MPEG Audio Layer 3

.WMA ---> Windows Media Audio

.WAV ---> WAVE Form

File extensions for  Video

.AVI ---> Audio Video Interleaved (Audio / Video Integrated)

.MPG /.MPEG ---> Moving Picture Expert Group

.MOV ---> Movie, usually associated with files that open with Quick Time, the .MOV can sometimes be replaced by .QT (Quick Time)

.WMV ---> Windows Media Video

Extensions for Web Pages

.HTM ---> Hyper Text Markup

.PHP ---> Originally Personal Home Page Tools currently Hypertext Preprocessor but maintains the same original acronym.

.PDF ---> Portable Document File

.JS ---> Java Script 

Below we have an example of how MS Windows show different files extensions and icons

This is just a small sample of the meanings of file extensions, certainly, the list is almost endless and every day more extensions are added, know the most common will help us know what material we are working and even allow us to identify suspicious files; for those who want a comprehensive compilation of all extensions (or at least most) we recommend visiting this List Extensions