PDF format. Pdf format has almost become a universal file format, because one of the characteristics of this file format is that it can embed fonts in documents and faithfully preserve the original appearance of documents, so it can be unified across different operating systems and language platforms, unlike Word documents, which have different formats because of different versions, so it is very convenient to scan handwritten papers into PDF format for reference. Many well-known websites use PDF for users to download application forms and documents. Chinese translation of PDF is "portable document format".