PDF, or Portable Document Format, is a file format originally developed by Adobe in the early 1990s. PDF files are created by converting existing electronic or paper documents using the Adobe Acrobat software, essentially producing an uneditable image of the original document. Almost all common types of files can be converted into PDF format, including file types in the Microsoft Office suite. They are designed to be easily exchanged between users, but they do have some disadvantages.
Limited OS Support
PDF is only supported under the Windows and Mac operating systems. Linux and Unix users cannot create or view PDF files. Alternative formats such as HTML or RTF can be used across all platforms, and are a better option.
Difficult to Read
Files in PDF format can prove difficult to read on a computer screen. PDF files are laid out in standard A4 or A3 format pages, which is great for printing, but most computer screens fall somewhere between a 4:3 and 16:9 aspect ratio, which means you spend a lot of time scrolling through the pages when viewing them on the screen.
There are two different types of PDF files, native and scanned. A native PDF has been converted directly from an electronic file, such as a Microsoft Word document; a scanned PDF is one that has been created by scanning a physical paper document through a scanner to produce an image of the document. Native PDFs are more flexible in that you can copy information, such as text, and paste it elsewhere, but scanned PDFs have very limited flexibility.
Difficult to Edit
A PDF file is essentially an uneditable image of the original document. This is great is terms of security, but PDF fails as a collaborative format. If your PDF file is native, it is possible to use software to extract the information into a usable form. However, if you have a scanned PDF document, there is no way to easily convert it back to an editable form.
PDF files are not always fully integrated into Web pages. If the user has an Adobe Reader or other PDF reader plug-in installed, PDF files can be viewed within the user's Internet browser. However, if no plug-in is installed, the user will be prompted to download and view the file in a separate application.