Glossary of Computer File Formats

We’ve all received a computer file we didn’t know how to open. The secret to identifying a compatible software program lies in the three- or four-letter extension at the end of the file name—which, for many of us, is a meaningless alphabet soup. This glossary will help you unscramble the mystery letters.

AVI

DOC
If you use Microsoft Word to type genealogy notes or correspondence, the resulting files are DOCs.

FDB
Legacy Family Tree genealogy software’s native file format.

FTW
Family Tree Maker software’s native file format.

GED
GEDCOM (short for Genealogical Data Communication). When genealogists who use different family tree programs want to share family files, they can convert their data to this standard file format any genealogy software can open.

GIF
Graphics Interchange Format. Most image-editing software, such as Adobe Photoshop Elements or Jasc Paint Shop Pro, can open this graphics format for still and animated images. Excellent for simple images that contain text, it’s most often used for simple Web graphics with a small number of colors (not photos).

HTML
Hypertext Markup Language. This is the predominant programming language for Web pages. Open an HTML file in Internet Explorer or another Web browser to view the “finished” page; use an HTML or plain-text editor such as Notepad to see or change the coding.

JPG
Also JPEG, it’s short for Joint Photographic Experts Group. JPG has become the most widely used format for static photographic images because it can display millions of colors. Any image-editing software can read a JPG.

MOV
Apple Quicktime Movie. MOV is probably the most common multimedia format for saving video or movie files, and is compatible with both Macintosh and Windows platforms.

MP3
One of the most popular audio formats, MP3 compresses sound clips into small files without losing quality. You can play MP3s on a portable device such as an iPod, or software such as iTunes and Real Player.

MPEG
Moving Picture Experts Group. Any Mac or Windows video player can read this video format, popular for creating movies that get distributed over the Internet. The related MPEG-4 format uses separate compression for audio and video tracks.

PAF
Data files created by Personal Ancestral File software. Several other genealogy software programs, including Family Tree Maker, Legacy and RootsMagic, can import PAF files directly.

PDF
Portable Document Format. Created to ease document exchange, PDF lets you view a file exactly as designed without the program that created it. All you need is the free Adobe Reader.

PJC
The extension for files created by The Master Genealogist software, which can directly import the native file formats of most popular genealogy programs.

PNG

RMG
RootsMagic genealogy software’s native file format.

SIT

TIFF
Tagged Image File Format. Good for bitmap (pixel-based) images, such as photographs. Since TIFF produces large files, it’s excellent if the end use is print (not Web) or archival.

TXT
Refers to plain-text files with little formatting; for example, no bold or italics. This format is most commonly used in simple text editors such as Windows Notepad and Mac TextEdit, but you can open them in almost any program that that can read a plain-text file (including word processors), making them good for file sharing.

WAV
Short for waveform, WAV is the standard format for storing audio on a PC. You can play WAV files on Windows or Mac in a program such as Windows Media Player or iTunes.

WMA

ZIP
Similar to SIT, ZIP format uses Zip compression to compress a document or documents into one smaller file for sharing or archiving. Windows users can create ZIP files using a program such as WINZIP, while Mac OSX users can simply Control-click a file and select Create Archive of “file name”.