What’s A PDF?

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Adobe Acrobat – as of this writing, it’s going for about $280

You’ve probably viewed and/or downloaded them countless times, and wondered why you need a special “reader” program for them. You may have noticed “PDF” listed among the compatible file types for e-reader devices like the Kindle Paperwhite and Kindle Fire, meaning that those devices can display PDFs without any special, additional software. You may have wondered why the PDFs you’ve downloaded can’t be edited, like any other text-based document. You may have wondered why PDFs exist at all.

PDFs: they’re here to stay, and here’s the skinny.

What’s A PDF?

PDF stands for Portable Document Format, and it’s a file type that was invented by software developer Adobe to answer the need for a document type that could be shared with others, but could only be edited by the person who created it.

A PDF is essentially a “picture” of a document or file that was originally in some other format. Imagine taking a page out of a book and asking an artist to draw a picture of the page. The resulting page, an artist’s rendering, could be read just like the original page, but it wouldn’t be possible to edit the words on the rendering. The only way to change the artist’s rendering would be to have a whole new rendering made. A PDF is like a rendering of an original file that might have been in MS Word, MS Excel, or virtually any other file format.

Adobe accomplished this feat by creating two different software programs: a PDF maker (Adobe Acrobat) to create the ‘renderings’ and a PDF reader (Acrobat Reader) to allow people to view the renderings. They made the Reader program freely available at no cost to anyone who wanted to download it, but charged a considerable fee for the Acrobat program.

PDFs Are “Lightweight”

When you create a file in a computer program, like a letter in Microsoft Word, it isn’t just the content of the letter that determines how big the file is. Your MS Word file also contains formatting and other computer instructions, so that the next time you open it, your MS Word program will “know” how to display it and what program options to set for it.

Since a PDF is just a picture of a file, it doesn’t need to contain all that program-specific information that’s in the original file. Therefore, PDF files are usually MUCH smaller than other types of files. That’s why it’s become the most popular format for sharing files and documents online: smaller files move across the internet more quickly than large ones.

PDFs Can Be Created From Scratch, Or “Printed”

This is the PDF maker program I use, though I have an earlier version from a couple years back. As of this writing, version 8 is priced at $17.49.

Web developers, form designers, and other pros will often create a PDF from scratch right in a PDF maker program, but it’s also possible to use a PDF maker like a printer. When you install a PDF maker program, it adds itself to your Printers list so you can select it as a printer option. When you “print” to the PDF maker, it creates a PDF version of your file.

Since PDF files are small, this can be a great way to get around email attachment file size limitations. If the PowerPoint slideshow you want to send is rejected by your email program as too big to use as an attachment, printing it as a PDF will often get the file down to an acceptable size.

Using a PDF maker like a printer is also a great way to go paperless when you want to save an online file or receipt, but don’t want to print out or store a hard copy. For example, I make most of my bill payments online, and I print a PDF copy of every payment confirmation page. There’s no wasted paper or printer ink, and the tiny files don’t take up much space on my hard drive, but the payment information is available to me if I need it in the future.

Is A PDF Really Totally Secure From Editing?

No. Anyone who has the Adobe Acrobat program, or any other PDF maker program, can not only create new PDFs but also edit any pre-existing PDF.

When Adobe Acrobat first came out, around 1993, it was an expensive program that was mostly used only by designers, engineers, and other professionals whose employers were paying for the program. At that time, it was a pretty safe bet that most people you sent a PDF to would not be able to edit it.

But in 2008, the PDF format became an “open” standard, meaning that other software developers could create PDF maker and reader programs of their own. Nowadays, there are lots of PDF maker programs available, some priced at around $20 or less.

What About Fill In The Blank, PDF Forms? Don’t They HAVE To Be Editable?

Some businesses and government agencies provide fill-in-the-blank forms on their websites in PDF format. This is an option that’s available in PDF maker programs when a PDF is created: the creator can make certain areas of the PDF “fields”, meaning areas that will allow the viewer to enter text. These online PDF forms will have a ‘Submit’ button at the bottom, so when you’re done filling out the form all the data you entered can be sent to the company or agency that runs the website.

However, if you have much experience with these PDF forms, you may have discovered that if you try to download or otherwise save a PDF form and then open it in a PDF viewer, the file you’ll get is a plain old, NON-editable PDF. This is more a function of the viewer program than the file itself; the viewer program was only designed to display PDFs, not to allow editing.

So THAT’S Why…

…PDFs exist, and why for most people, they’re not editable.

I strongly suggest picking up a PDF maker program, just for the paperless aspect alone. You’ll find yourself “printing” to PDF on a near-daily basis once you’ve got the program, and the program will pay for itself in paper and ink savings pretty quickly.


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  1. Comment by Dennis Gore:

    Excent article Mom. But I’m a little confused, would’nt the “PDF” file be like putting all your files into a big box and trying to find one months later when you need it. Impossible No. How would anyone be able to have a file system that would not be very cluttered.
    I realy like your idea of using a paperless file system, but like I said I’m confused, How do you make that file system Mum.;)

    • Comment by Mom:

      Since each PDF is a separate, individual file, you just name them in a way that makes them easy to find. My naming convention is [companyname][mmyy]. So for example, when I paid my phone bill last month I saved the PDF as VerizonFios0213. Then I save ALL of those confirmation printouts in a single folder called “Bills”.