What are file formats?

A computer file format is a particular way to encode information for storage on a computer.

Some file formats such as .pub, or .docx – may not open on a MAC as they need the file reader or program that created the file.

The .docx file can be opened on the Mac if the Microsoft Office Word program has been downloaded. Whereas .pub files are a Microsoft Publishing program that is not available on Mac computers.

Mac file formats like .pages can not be read on a PC for the same reason.

There are many different types of file formats – if you cant read or open a file – do some research to find out why.


 In your search engine ask the question

E.g.: why can’t I read this .pub file (you will find that the sender will need to convert the .pub to an interchangeable format such as .PDF or .JPG

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 Inter changeable file formats – you can read on any computer.

.GIF (Graphic Interchange Format) files use a maximum of 256 colors, and are best for displaying noncontinuous-tone images or those with large areas of flat colors, such as navigation bars, buttons, icons, logos, or other images with uniform colors and tones.

.JPEG (Joint Photographic Experts Group) file format is the superior format for photographic or continuous-tone images, because JPEG files can contain millions of colors. As the quality of a JPEG file increases, so does the file size and the file download time. You can often strike a good balance between the quality of the image and the file size by compressing a JPEG file.

.PNG (Portable Network Group) file format is a patent-free replacement for GIFs that includes support for indexed-color, grayscale, and true-color images, and alpha channel support for transparency. PNG is the native file format of Macromedia Fireworks MX. PNG files retain all the original layer, vector, color, and effects information (such as drop shadows), and all elements are fully editable at all times. Files must have the .png file extension to be recognized as PNG files by Macromedia Dreamweaver MX.

.TIF, .TIFF Tagged Image File Format. Used to exchange documets between different applications and platforms. ….

.pdf Portable Document File format. Adobe document reader that allows portability. Often used on the Web for better control of page layout.

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 Examples of file formats


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


.csv Comma Separated Values File
.dat Data File
.gbr Gerber File
.ged GEDCOM Genealogy Data File
.key Keynote Presentation
.keychain Mac OS X Keychain File
.pps PowerPoint Slide Show
.ppt PowerPoint Presentation
.pptx PowerPoint Open XML Presentation
.sdf Standard Data File
.tar Consolidated Unix File Archive
.tax2012 TurboTax 2012 Tax Return
.tax2014 TurboTax 2014 Tax Return
.vcf vCard File
.xml XML File


.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


.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
.m4v iTunes Video File
.mov Apple QuickTime Movie
.mp4 MPEG-4 Video File
.mpg MPEG Video File
.rm Real Media File
.srt SubRip Subtitle File
.swf Shockwave Flash Movie
.vob DVD Video Object File
.wmv Windows Media Video File


.bmp Bitmap Image File
.dds DirectDraw Surface
.gif Graphical Interchange Format File
.jpg JPEG Image
.png Portable Network Graphic
.psd Adobe Photoshop Document
.pspimage PaintShop Pro Image
.tga Targa Graphic
.thm Thumbnail Image File
.tif Tagged Image File
.tiff Tagged Image File Format
.yuv YUV Encoded Image File


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


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


.apk Android Package File
.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


.asp Active Server Page
.aspx Active Server Page Extended File
.cer Internet Security Certificate
.cfm ColdFusion Markup File
.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 PHP Source Code File
.rss Rich Site Summary
.xhtml Extensible Hypertext Markup Language File

For more information –  http://fileinfo.com/filetypes/common