I use the pdf4free freeware. You can of course purchase the Adobe product.
There are other options such as the Visio Viewer, SVG, save as html, etc.
al
PDFs are created by using a program that "pretends" to be a printer driver.
Rather than sending the information to a printer, it converts it to a PDF
file. Since most programs use printers, these "printer drivers" will create
PDFs from these programs.