There are two types of PDFs:
To use it, simply type your search term followed by the operator in a search engine like Google or Google Scholar : Example: "artificial intelligence trends filetype:pdf" How Search Engines Index PDFs
Professional results, handles OCR automatically. Cons: Requires a monthly subscription ($12.99+/month).
Search engines like Google treat PDFs similarly to standard HTML pages. If a PDF is not password-protected or encrypted, Google can index its text, including different languages and character encodings.
I notice you're asking for a "type pdf: provide a complete post" — this seems a bit ambiguous.
You could be looking for a way to make a PDF document that someone else can type into (a "fillable form").