Typical use cases for PDF are eBooks, brochures, legal documents, and documents you want to print or display while preserving a specific style and format. This ensures that said document is displayed the way you want regardless of the device it is opened on. This is why PDFs are often used when sending a document electronically since they preserve the original document's formatting, including links, images, fonts, and styles. Simply put, PDF is device and OS-agnostic. PDF, or Portable Document Format, is a popular file format as it allows documents to be exchanged regardless of the end user's software, hardware, or operating system.
Both have pros and cons, and under certain situations, no doubt that one may be better than the other. When it comes to document formats, there are two that are widely used: PDF and DOC.