Science Teaching Series

Internet Resources

I. Developing Scientific Literacy

II. Developing Scientific Reasoning

III. Developing Scientific Understanding

IV. Developing Scientific Problem Solving

V. Developing Scientific Research Skills

VI. Resources for Teaching Science

File Extensions

Multipurpose Internet Mail Extensions (MIME) and File Extensions: When sending files over the Internet a file name extension must be be attached to a file. The extension identifies the file as either text or binary. The receiving end uses the file name extension to determine what kind of file it is and what program is expected to open or use the data. When a browser asks for a file to be retrieved, it sends the server a list of the file types it can handle. The server then examines the list and the requested file name extension and matches the correct transmission method to the file. In the same way, when an e-mail attachment contains a file, the sender's mail client will attach a MIME type to the file. Where browsers and FTP clients use file extensions to determine the file type, e-mail clients use the MIME type to determine the action at the receiving end.

Download extension glossary (Excel format)

Complete Listing & Source (Per Christensson www.sharpened.net)

Extension

Definition and Description

Program to Open the File

.aac

Advanced Audio Coding File
- a highly compressed audio file that maintains quality nearly indistinguishable from the original audio source

Mac / Windows: Apple iTunes

.arc

Macintosh Hierarchical Archive
- a self-extracting compressed file

Mac: Opens itself
Windows: Stuffit Expander

.aiff

Audio Interchange File Format
- sound file, similar to .wav

Mac / Windows: Audio or media application (QuickTime / Windows Media Player)

.asmx

Active Server Method File
- defines Web services called by an Active Server Page (see below)

Windows: Microsoft Windows-based Web server with the .NET framework

.asp

Active Server Page
- server-generated HTML Web page based on ActiveX scripting

Mac / Windows: Web browser, such as Safari or Internet Explorer (ASP code is parsed by the Web server)

.aspx

Active Server Page Extended
- server-generated HTML Web page based on ActiveX scripting that uses the Microsoft .NET framework

Mac / Windows: Web browser, such as Safari or Internet Explorer (ASP code is parsed by the Web server)

.avi

Audio Video Interleave File
- high-quality video format; uses less compression than similar formats such as .mpeg and .mov

Mac / Windows: Any movie player (QuickTime, Windows Media Player)

.bat

DOS Batch File
- contains a series of line commands; runs itself

Windows: Any text editor

.bin

Macbinary II Encoded File
- a compressed file encoded as binary or MacBinary

Mac: Stuffit Expander

.cer

Internet Security Certificate
- a security file provided by a third party such as VeriSign or Thwate that confirms the authenticity of a Web site

Mac / Windows: Web server such as Apache or Windows 2000 Server

.cgi

Common Gateway Interface Script
- written in C or Perl; can only be edited if it is not pre-compiled

Mac / Windows: Any text editor

.cif

CD Disk Image
- CD image format created by Corel and used by Roxio CD Creator; mounts as a physical CD

Windows: Roxio Media Creator, MagicISO

.css

Cascading Style Sheet
- used for formatting the contents of a Web page, such as font type, size, and color, as well as table layout and spacing

Mac / Windows: Editable with any text editor, used by HTML pages

.csv

Comma Separated Values
- contains data separated by commas and each new line represents a new row; values can be organized into cells by a spreadsheet program

Mac / Windows: Any spreadsheet program, such as Microsoft Excel

.dat

Data File
- written by an application and typically accessed only by that application

Windows: Any text editor

.db

Database File
- generic database file, could be created by a number of different database programs

Mac / Windows: A compatible database program such as FileMaker Pro or MS Access

.dbx

Microsoft Visual Foxpro Table File
- contains a Foxpro table

Mac / Windows: FoxPro or other database program

.dll

Dynamic Link Library
- a compiled set of procedures and/or drivers called by another program

Windows: a compiled program that should not be edited

.dmg

Disk Image
- a mountable disk image file; opening the image file will mount a virtual disk on the Desktop

Mac OS X: Apple Disk Utility
(not compatible with Mac OS 9)

.doc

Microsoft Word Document
- a document created by Microsoft Word or WordPad

Mac / Windows: Microsoft Word

.dot

Microsoft Word Template
- a template for new Microsoft Word documents

Mac / Windows: Microsoft Word

.eml

Outlook Express Saved Message
- message that was saved in Outlook

Mac / Windows: Microsoft Outlook

.eps

Encapsulated PostScript
- PostScript (.ps) file typically containing images, vector graphics, and text. Has an embedded preview image; often used for transferring between different operating systems.

Mac / Windows: Adobe Illustrator, Acrobat, or Photoshop; most image-editing programs can at least view the preview image

.exe

Executable File
- DOS/Windows program or self-extracting archive

Windows: Runs itself

.fpt

FileMaker Pro File
- database created by FileMaker Pro

Mac / Windows: FileMaker Pro

.gif

Graphical Interchange Format
- image file that uses up to 256 indexed colors; common format for Web graphics

Mac / Windows: Any picture viewer or Web browser (Mac: Preview, Windows: Photo Editor)

.gp4

CCITT Group 4 File
- Fax document

Mac / Windows: Any fax program

.gz

Gnu zipped file
- compressed using the common method (Gnu) on UNIX systems

Mac: Stuffit Expander
Windows: WinZIP

.hlp

Windows help File
- documentation for Windows or Windows programs

Windows: Windows Help Viewer (integrated into Windows)

.htm
.html

HTML File
- HTML coded page to be displayed in a Web browser; .htm is the extension typically used by Microsoft FrontPage

Mac / Windows: Web browser (Netscape / Internet Explorer)

.hqx

BinHex 4.0 encoded File
- Macintosh file compressed and encoded into 7-bit text; helps maintain file integrity for downloads

Mac: Stuffit Expander

.ico

Icon File
- Windows icon file format; can be used to change file icons

Windows: Part of the operating system

.img

Macintosh Disk Image
- can be mounted like a disk; acts like a hard disk when mounted

Mac OS 9: Apple Disk Copy or Aladdin ShrinkWrap
Mac OS X: Apple Disk Utility
Windows: MagicISO

.ini

Initialization File
- contains settings for Windows programs; can be edited, but typically shouldn't be

Windows: Any text editor

.jar

Java Archive File
- contains multiple Java files; can be compressed, digitally signed, and run as a program

Mac / Windows: Any program that supports Java 1.1 or later

.jpeg
jpg

Joint Photographic Experts Group File
- 24-bit compressed graphic format; common format for Web graphics

Mac / Windows: Any picture viewer or Web browser (Mac: Preview, Windows: Photo Editor)

.js

JavaScript file
- a text file containing JavaScript code; often referenced by Web pages that incorporate JavaScript functions

Mac / Windows: Any text editor (for editing); any Web browser (to compile and run the JavaScript code)

.kpg

Kai's Power Goo Graphic
- image file edited and saved in Kai's Power Goo

Mac / Windows: Kai's Power Goo (Scansoft)

.lit

eBook File
- electronic version of a book or other publication

Windows: Microsoft Reader

.lnk

File Shortcut (or Link)
- a link or alias to the original file; an icon that points to the actual file

Windows: Windows Operating System

.log

Log File
- text file that keeps a log of certain events; used by operating systems, installers, Web servers, and many other programs

Mac / Windows: Any text editor

.m4a

MPEG-4 Audio Layer
- audio file that uses MPEG-4 audio compression; basically an .mp4 file without the video track

Mac / Windows: Apple iTunes or QuickTime Player, Windows Media Player, or other audio program that supports MP4 compression

.max

Paperport File
- document converted by Scansoft Paperport

Mac / Windows: Paperport Viewer

.mdb

Microsoft Access Database
- database file (including, tables, forms, queries, etc.) created by Microsoft Access

Mac / Windows: Microsoft Access

.mid
.midi

MIDI File
- Musical Instrument Digital Interface standard file; contains music data such as what notes are played, when they are played, how hard the key is pressed, how long it is held, etc.

Mac / Windows: QuickTime Player or other audio program that supports MIDI

.mim
.mime

Multi-Purpose Internet Mail
- common encoding for e-mail attachments

Mac: Stuffit Expander
Windows: WinZip

.mp3
.mpu

Moving Picture Experts Group 3 Layer Audio
- compressed audio format; near-CD quality sound (stereo, 16-bit)

Mac / Windows: iTunes or other music player

.mp4

MPEG-4 Video File
- video clip or movie that uses MPEG-4 compression

Mac / Windows: Apple QuickTime Player

.mpg
.mpeg

Moving Picture Experts Group File
- common video format; often used for downloadable movies

Mac / Windows: Any movie player (QuickTime, Windows Media Player)

.mpp

Microsoft Project File
- created for organizing, tracking, and maintaining projects

Windows: Microsoft Project

.mov
.moov

Apple QuickTime Movie
- common multimedia format; cross-platform, but developed by Apple

Mac / Windows: Apple QuickTime Player

.ns2
.ns3
.ns4

Lotus Notes Database
- database file created by Lotus Notes 2, 3, or 4

Mac / Windows: Lotus Notes

.ocx

ActiveX Control
- an object that can be placed within an ActiveX form and can have an event attached to it

Windows: ActiveX development software

.old

Backup File
- often used as an indicator for a backup copy of a file; often placed after the orginal suffix (i.e. document.doc.old)

Mac / Windows: Original program used to create file

.p65

PageMaker 6.5 Document
- page layout document created by Adobe PageMaker

Mac / Windows: Adobe Pagemaker 6.5 or greater

.pab

Personal Address Book
- address book file for Microsoft e-mail programs

Mac: Microsoft Outlook/Entourage
Windows: Microsoft Outlook/Exchange

.pct

Picture File
- an image file formatted in the Macintosh PICT format

Mac / Windows: Any image viewing program with PICT support, i.e. Adobe Photoshop

.pdf

Portable Document Format
- cross-platform document created by Adobe Acrobat

Mac / Windows: Adobe Acrobat Reader (free) or Adobe Acrobat (commercial version)

.pfc

AOL Personal File Cabinet
- file system for America Online

Mac / Windows: update using AOL

.pl

Perl Script
- text (ASCII) file that can be compiled and run on Unix

Mac / Windows: Any text editor

.png

Portable Network Graphic
- lossless image format that uses indexed colors (like a GIF), but without copyright issues

Mac / Windows: Most picture viewers and Web browsers (Mac: Preview, Windows: Photo Editor)

.pps

Powerpoint Slide Show
- slide show created by Microsoft Powerpoint

Mac / Windows: Microsoft PowerPoint or PowerPoint Viewer

.ppt

PowerPoint Presentation
- editable slide show created by Microsoft Powerpoint

Mac / Windows: Microsoft PowerPoint

.ps

Postscript File
- saved in printer-readable format, often consisting of vector graphics and text; can be printed directly without being opened in an application

Mac / Windows: Adobe Illustrator, Acrobat, or Photoshop; any printer utility that supports Postscript

.psd

Photoshop Document
- document created by Photoshop; can include layers, filters, and other Photoshop specific elements

Mac / Windows: Adobe Photoshop

.pst

Personal Folder File
- contains personal information for Microsoft e-mail programs

Mac: Microsoft Outlook/Entourage
Windows: Microsoft Outlook/Exchange

.pub

Publisher Document
- Microsoft Publisher file

Windows: Microsoft Publisher

.qt

Apple QuickTime Movie
- common multimedia format; cross-platform, developed by Apple

Mac / Windows: Apple QuickTime Player

.qxd

QuarkXpress Document
- QuarkXpress desktop publishing file

Mac / Windows: QuarkXpress

.ra
.ram

Real Audio
- audio file created by RealPlayer

Mac / Windows: RealPlayer

.rar

WinRAR Compressed Archive
- a compressed file or group of files; uses a higher compression ratio than typical ZIP compression

Mac: Stuffit Expander
Windows: WinRAR

.rtf

Rich Text Format
- text file that includes formatting such as bold type, italics, different fonts and font sizes, etc.

Mac / Windows: Any text editor that supports text formatting

.rm

Real Media
- media file created by RealPlayer

Mac / Windows: RealPlayer

.sea

Self-Extracting Archive
- compressed Macintosh file that opens and uncompresses itself

Mac: opens itself
Windows: Stuffit Expander

.sit

Stuffit Archive
- compressed file "stuffed" by Aladdin Stuffit program; originally Mac-only, now cross-platform

Mac / Windows: Stuffit Expander

.smi

ShrinkWrap Disk Image
- disk image created by ShrinkWrap; mounts as a disk when opened

Mac: Aladdin ShrinkWrap or Apple Disk Copy

.sql

Structured Query Language Data
- database file written in SQL; can be read by any compatible database

Mac / Windows: Any text editor or SQL-compatible database program such as Microsoft Access

.swf

Macromedia Flash Movie
- vector-based animation created by Macromedia Flash; plays automatically in Web browser if Flash plug-in is installed

Mac / Windows: Macromedia Flash Player or Web browser with Flash plug-in installed

.swp

Swap File
- used by the operating system to swap information from memory to the hard disk; acts as virtual memory or simply a memory buffer

Mac / Windows: non-editable

.sys

System File
- stores system settings and variables for DOS and Windows; typically should not be edited

Windows: Any text editor

.tar

Consolidated File Archive (Unix)
- multiple files stored as one archive via Unix tar program; often compressed with Gnu Zip as well

Mac: Stuffit Expander
Windows: WinZip

.tiff

Tagged Image File Format
- high quality graphics format

Mac / Windows: Any picture viewer (Mac: Preview, Windows: Photo Editor)

.tga

Targa Graphic
- a texture file, often used in games

Mac / Windows: QuickTime Player

.tmb

Timbuktu Pro Document
- remote access control file

Mac: Timbuktu Pro

.txt

Text File
- file containing only text

Mac / Windows: Any text editor

.uu
.uue

Uuencoded File
- encoded by Unix uuencode

Mac: UU Undo
Windows: WinCode

.vsd

Visio Drawing File
- diagram created by Visio

Windows: Microsoft Visio

.wav

Windows WAVE Sound File
- high-quality audio file, similar to AIFF

Mac / Windows: Audio or media application (QuickTime / Windows Media Player)

.wk1

Lotus Worksheet
- spreadsheet created by Lotus

Mac / Windows: Lotus 1-2-3 or Microsoft Excel

.wma

Windows Media Audio
- audio file compressed with Windows Media compression

Mac / Windows: Windows Media Player

.wmf

Windows Metafile
- proprietary Windows graphic format

Windows: Xara X or compatible Windows viewing program

.wmv

Windows Media Video
- video/audio file compressed with Windows Media codec

Mac / Windows: Windows Media Player

.wpd

Word Perfect Document
- text document created by Corel WordPerfect

Mac / Windows: Corel WordPerfect

.wpt

Word Perfect Document
- template for Corel WordPerfect documents

Mac / Windows: Corel WordPerfect

.wpm

Word Perfect Macro
- macro file for Corel WordPerfect

Mac / Windows: Corel WordPerfect

.xls

Microsoft Excel Spreadsheet
- spreadsheet created by Microsoft Excel

Mac / Windows: Microsoft Excel

.xlw

Microsoft Excel Workbook
- workbook containing multiple items created by Microsoft Excel

Mac / Windows: Microsoft Excel

.xlt

Microsoft Excel Template
- template for new Microsoft Excel documents

Mac / Windows: Microsoft Excel

.xml

Extensible Markup Language File
- a data file that uses tags (like HTML) to define objects and object attributes; a text-based database

Mac / Windows: Any text editor

.ymg
.yps

Yahoo Messenger File
- written by Yahoo Messenger

Mac / Windows: Yahoo Messenger

.z

Unix Compressed File
- compression format for some files on Unix servers

Mac: Stuffit Expander
Windows: WinZip

.zip

Zipped File
- compressed by PKZip or WinZip; typically used with Windows files

Mac: Stuffit Expander
Windows: WinZip