Here's some info about Acrobat.
Adobe created the PDF document format so that it can be read and printed by almost any host, be it a PC, a Mac or a Unix machine. This eliminates the problem of having to post a PC Word version, a PC WordPerfect version, a Mac version, a Unix Postscript version, etc. In addition, the PDF format perserves pagination. That is, page 234 for you is the same as page 234 for anyone else, no matter what machine or printer they use.
Many companies have adopted the PDF format for their documentation. So, no matter what type of computer and printer you have, when you download and print a PDF document, page 27 is page 27, not page 25 or 31 - because you didn't use the right font or have the right word processor.