<human>: What is the difference between a PDF and a DOC file?
<bot>: The main difference between a PDF and a DOC file is that a PDF file is a more secure way of sharing documents. A PDF file is a type of digital document that can be viewed across different platforms, while a DOC file is only compatible with certain programs. Additionally, PDFs are usually smaller in size than DOC files because they do not contain unnecessary formatting or images.