Common file type with Extension

Text Files
.doc	Microsoft Word Document
.docx	Microsoft Word Open XML Document
.log	Log File
.msg	Outlook Mail Message
.pages	Pages Document
.rtf	Rich Text Format File
.txt	Plain Text File
.wpd	WordPerfect Document
.wps	Microsoft Works Word Processor Document

Data Files
.csv	Comma Separated Values File
.dat	Data File
.efx	eFax Document
.gbr	Gerber File
.key	Keynote Presentation
.pps	PowerPoint Slide Show
.ppt	PowerPoint Presentation
.pptx	PowerPoint Open XML Presentation
.sdf	Standard Data File
.tax2010	TurboTax 2010 Tax Return
.vcf	vCard File
.xml	XML File

Audio Files
.aif	Audio Interchange File Format
.iff	Interchange File Format
.m3u	Media Playlist File
.m4a	MPEG-4 Audio File
.mid	MIDI File
.mp3	MP3 Audio File
.mpa	MPEG-2 Audio File
.ra	Real Audio File
.wav	WAVE Audio File
.wma	Windows Media Audio File

Video Files
.3g2	3GPP2 Multimedia File
.3gp	3GPP Multimedia File
.asf	Advanced Systems Format File
.asx	Microsoft ASF Redirector File
.avi	Audio Video Interleave File
.flv	Flash Video File
.mov	Apple QuickTime Movie
.mp4	MPEG-4 Video File
.mpg	MPEG Video File
.rm	Real Media File
.swf	Shockwave Flash Movie
.vob	DVD Video Object File
.wmv	Windows Media Video File

3D Image Files
.3dm	Rhino 3D Model
.max	3ds Max Scene File

Raster Image Files
.bmp	Bitmap Image File
.gif	Graphical Interchange Format File
.jpg	JPEG Image File
.png	Portable Network Graphic
.psd	Adobe Photoshop Document
.pspimage	PaintShop Pro Image
.thm	Thumbnail Image File
.tif	Tagged Image File
.yuv	YUV Encoded Image File

Vector Image Files
.ai	Adobe Illustrator File
.drw	Drawing File
.eps	Encapsulated PostScript File
.ps	PostScript File
.svg	Scalable Vector Graphics File

Page Layout Files
.indd	Adobe InDesign Document
.pct	Picture File
.pdf	Portable Document Format File
.qxd	QuarkXPress Document
.qxp	QuarkXPress Project File
.rels	Open Office XML Relationships File

Spreadsheet Files
.xlr	Works Spreadsheet
.xls	Excel Spreadsheet
.xlsx	Microsoft Excel Open XML Spreadsheet

Database Files
.accdb	Access 2007 Database File
.db	Database File
.dbf	Database File
.mdb	Microsoft Access Database
.pdb	Program Database
.sql	Structured Query Language Data

Executable Files
.app	Mac OS X Application
.bat	DOS Batch File
.cgi	Common Gateway Interface Script
.com	DOS Command File
.exe	Windows Executable File
.gadget	Windows Gadget
.jar	Java Archive File
.pif	Program Information File
.vb	VBScript File
.wsf	Windows Script File

Game Files
.gam	Saved Game File
.nes	Nintendo (NES) ROM File
.rom	N64 Game ROM File
.sav	Saved Game

CAD Files
.dwg	AutoCAD Drawing Database File
.dxf	Drawing Exchange Format File

GIS Files
.gpx	GPS Exchange File
.kml	Keyhole Markup Language File

Web Files
.asp	Active Server Page
.cer	Internet Security Certificate
.csr	Certificate Signing Request File
.css	Cascading Style Sheet
.htm	Hypertext Markup Language File
.html	Hypertext Markup Language File
.js	JavaScript File
.jsp	Java Server Page
.php	Hypertext Preprocessor File
.rss	Rich Site Summary
.xhtml	Extensible Hypertext Markup Language File

Plugin Files
.8bi	Photoshop Plug-in
.plugin	Mac OS X Plug-in
.xll	Excel Add-In File

Font Files
.fnt	Windows Font File
.fon	Generic Font File
.otf	OpenType Font
.ttf	TrueType Font

System Files
.cab	Windows Cabinet File
.cpl	Windows Control Panel Item
.cur	Windows Cursor
.dll	Dynamic Link Library
.dmp	Windows Memory Dump
.drv	Device Driver
.lnk	File Shortcut
.sys	Windows System File

Settings Files
.cfg	Configuration File
.ini	Windows Initialization File
.keychain	Mac OS X Keychain File
.prf	Outlook Profile File

Encoded Files
.bin	Macbinary Encoded File
.hqx	BinHex 4.0 Encoded File
.mim	Multi-Purpose Internet Mail Message File
.uue	Uuencoded File

Compressed Files
.7z	7-Zip Compressed File
.deb	Debian Software Package
.gz	Gnu Zipped Archive
.pkg	Mac OS X Installer Package
.rar	WinRAR Compressed Archive
.rpm	Red Hat Package Manager File
.sit	StuffIt Archive
.sitx	StuffIt X Archive
.tar.gz	Tarball File
.zip	Zipped File
.zipx	Extended Zip File

Disk Image Files
.dmg	Mac OS X Disk Image
.iso	Disc Image File
.toast	Toast Disc Image
.vcd	Virtual CD

Developer Files
.c	C/C++ Source Code File
.class	Java Class File
.cpp	C++ Source Code File
.cs	Visual C# Source Code File
.dtd	Document Type Definition File
.fla	Adobe Flash Animation
.java	Java Source Code File
.m	Objective-C Implementation File
.pl	Perl Script
.py	Python Script

Backup Files
.bak	Backup File
.gho	Norton Ghost Backup File
.ori	Original File
.tmp	Temporary File

Misc Files
.dbx	Outlook Express E-mail Folder
.msi	Windows Installer Package
.part	Partially Downloaded File
.torrent	BitTorrent File