What is a PDF file?
Adobe PDF files—short for portable document format files—are one of the most commonly used file types today. If you've ever downloaded a printable form or document from the Web, such as an IRS tax form, there's a good chance it was a PDF file. Whenever you see a file that ends with .pdf, that means it's a PDF file.
Why use PDF files?
Let's say you create a newsletter in Microsoft Word and share it as a .docx file, which is the default file format for Word documents. Unless everyone has Microsoft Word installed on their computers, there's no guarantee that they would be able to open and view the newsletter. And because Word documents are meant to be edited, there's a chance that some of the formatting and text in your document may be shifted around.
By contrast, PDF files are primarily meant for viewing, not editing. One reason they're so popular is that PDFs can preserve document formatting, which makes them more shareable and helps them to look the same on any device. Sharing the newsletter as a PDF file would help ensure everyone is able to view it as you intended.
Opening PDF files
Opening and viewing a PDF file is pretty simple. Most modern web browsers will open PDF files directly in your browser window instead of downloading them to your computer. If your browser can't do this, it should prompt you to download the file instead.
If you need to view a PDF file just once, it's usually easiest to open it in your web browser. If you need to access the PDF later, you'll want to save a copy to your computer. This process will vary depending on your web browser, but typically there will be a small disc icon in the upper right of your PDF document window.