In the digital world, PDFs meet all of the industry standards for publishing. For example, have you ever emailed a document to someone and they complained that the formatting was all messed up when they opened it? Maybe they couldn't even open the file because they didn't have the right program.
Not every computer has the same programs, program versions or even the same fonts. And what looks fine on your computer might look terrible, or not even open at all, on someone else's system. That's why the Portable Document Format (you probably know it as PDF) exists.
But no matter how digital our world has become, printed documents are still alive and kicking. From magazines to flyers, posters and door hangers, there's no evidence that traditional print is going anywhere anytime soon.
So no matter when you are designing or sending to other people, a PDF is the industry standard. All you have to find is the right PDF creator.