What is the primary characteristic of a .pdf file?

The primary characteristic of a .pdf file is that it can be downloaded but not easily edited. PDF, which stands for Portable Document Format, is designed to present documents in a manner independent of application software, hardware, and operating systems. This means that a PDF file preserves the formatting, fonts, and layout of the document, allowing it to be viewed consistently across different platforms and devices.

While it is possible to edit PDF files using specific software, this process is not straightforward and typically requires specialized tools, making it more cumbersome compared to formats like Microsoft Word or plain text files. The inherent design of PDFs is for sharing and viewing purposes rather than for frequent editing. Thus, it aligns with the primary characteristics of a PDF file that it can be easily downloaded but not easily edited without proper software.