Tech Skills Fundamentals What Is A PDF File

What exactly is a PDF?

Adobe PDF files, which stand for "portable document format" files, are one of the most common files used today. If you've ever printed a form or document from the Internet, like an IRS tax form, it was probably a PDF file. If a file's name ends in ".pdf," it's a PDF file.

Why should you use PDFs?

Let's say you make a newsletter in Microsoft Word and share it as an a.docx file, the default file format for Word documents. If everyone doesn't have Microsoft Word on their computers, they might not be able to open the newsletter and look at it. And because Word docs are meant to be changed, some of the formatting and text in your document might get moved around.

PDF files are mostly meant to be viewed and not changed. PDFs are so popular because they keep the formatting of documents. This makes sharing easier and helps them look the same on any device. Sharing the newsletter as a PDF would help ensure everyone can see it as you meant.

Opening PDF files

It's pretty easy to open and look at a PDF file. Most modern web browsers can open PDF files right in the browser window without downloading them. If your web browser can't do this, it should ask if you want to download the file. Click this link and see what happens on your computer.

Most of the time, it's easiest to open a PDF file in your web browser if you only need to look at it once. You should save a copy of the PDF to your computer in case you need to use it again later. Depending on your web browser, this process will be different, but in the example below, the Save PDF button is in the upper right corner.

If the PDF file is already on your machine, you can double-click it to open it with the default PDF program.

If your computer has Windows 7 or an older version, you may need to download a free PDF viewer like Adobe Reader before you can view PDF files.

Changes to PDF files

As we already said, PDFs are mostly meant to be looked at, not changed. But sometimes, you might come across a PDF that lets you type in information like your name and address. Form fields are a special part of these PDFs that let you type new details into the document and save your changes. For instance, this PDF has a few form fields where you can put your name, address, and other information.

Not all web browsers assist with this feature, so you may need to download the PDF before you can add your information using form fields.

You may also want to make small changes to PDF files, such as adding a comment or highlighting some text. Check out our lesson on editing and merging PDFs to learn more about editing PDF files.

Putting PDFs together

There are many ways to make PDF files, but how you do it will depend greatly on your device. For example, if you're using Windows 10, you can go to the Print dialogue box and choose PDF from the list of printers at the top. This lets you make a PDF of any document, email, or webpage that you would normally be able to print. On a Mac, you can save a file as a PDF through the Print dialogue box's PDF menu.

If your computer has Windows 8 or an older version, you can do a few different things. The simplest way is to use software like Microsoft Office or Google Chrome that can export to PDF.

Another option is a PDF converter like Smallpdf, a free app that runs in your web browser. Smallpdf can turn many file types, like Microsoft Office files, into PDF files.

PDF Advantages

Graphic Consistency

The content and layout of a PDF are the same no matter what operating system, device, or software is used to view it.


PDFs can include text, images, vector graphics, videos, animations, audio files, 3D models, interactive fields, hyperlinks, and buttons. All these things can be put together in one PDF file as a report, a presentation, or a portfolio.


PDFs are effortless for everyone to make, read, and use.


It offers ways to set up different access levels to protect the content and the whole document, like digital signatures, watermarks, and passwords.


PDFs can theoretically hold an unlimited amount of information. However, they can be shrunk into small files that are easy to share while still letting you control the image quality.

PDF Limitations

The PDF was made as a way for documents to be shared. The original goal was to keep and protect the content and layout of a document, no matter what platform or computer program it is viewed on. This is why it's hard to change PDFs and sometimes even hard to get information out of them.

Regarding how to work with them, PDFs are not all the same. There are different ways to work with different types of PDFs, such as when searching for information or pulling it out.