PDF stands for "Portable Document Format " and was developed by Adobe (the same company that sells Adobe Photoshop, Illustrator, Lightroom, and others). Developed in 1993, it took a while to catch on, but is now all over the Net. Adobe developed it to standardize documents.
A PDF will basically print out the same from printer to printer, which is why many use it (for things like guides, information sheets, reports). For instance, a Microsoft Word document's appearance will vary depending on what fonts are installed on each computer -- on your computer. With a PDF, the fonts and graphics are embedded within the document itself. It also uses postscript, a page definition language, to specify layout. Adobe's Reader (for reading PDF's) is free. It can be downloaded here. PDFs cannot be altered by the reader.
Although the Adobe Reader is free, Adobe's program to actually write PDFs, Acrobat, has often, in the past, been rather expensive. (Although the cheapest version has now come down to around $300. Part of the expensive is because Acrobat does turn simple WYSIWYG - What You See Is What You Get -- into postscript.)
As a result there are now many third-party programs and plug-ins, mainly for Word, that will export a file into PDF format. The newest version of Word, 2007, even has Save As... with PDF as a drop down menu choice. The resulting PDF document cannot be edited as a PDF, but one can create one from an existing word processing document.
When you click on a link that leads to a PDF, the Adobe Reader is actually opened inside your browser. This is why a PDF file often takes a while to load. First your browser finds the Adobe Reader installed on your machine, then it opens the Reader, then the Reader opens the PDF. If you don't have a Reader installed, you will see an error message.
Some people don't like the waiting and/or have problems with the Reader opening in their browser (sometimes it can freeze it, if the document is very long). That is why every link on these green pages that goes to a PDF will say PDF after the link.
If you want, you can save PDF files to your computer without ever opening them within your browser. When you know a link goes to a PDF, put your mouse cursor over it and right click. A menu will come up. Choose Save Target As... and the Save Dialog will come up. Then you can save it where you want on your computer.
The Word 2007 "Save As PDF" option is a downloadable add-in (free) from Microsoft. It will not work with any earlier version, but does not come with Word 2007 itself. You can download it here. Follow the installation instructions.
Excerpted from an original article by Marnie Parker
