The workflow for a print project refers to the steps that are necessary to produce the project and the order in which the steps are completed. The PDF (Portable Document Format) workflow refers to the steps that are necessary to produce a project with PDF as part of the entire process. PDF files are highly structured and are simple to use. With PDF, you can view and exchange files independent of the application in which they were originally created.
PostScript language has been the standard of desktop publishing and digital graphic arts production. Adobe systems developed this as a page description language (PDL). It is used primarily as a language for outputting documents on printers.
You don't have to choose between PDF and PostScript because each has its own purpose in the workflow. Use PDF as the standard for exchanging files and streamlining output. PostScript technology translates files into print.