PDF started life as a way for multiple platforms (Mac, Windows, *nix) to be able to view the same file in exactly the way the publisher intended- It's been extended and mutated a lot over the decades.
It's actually PostScript with a funny tasting shell wrapped around it, which Adobe invented for printers and typography to get around the same problem. (allowing multiple platforms to send data to a printer and have consistent results regardless of who sent the data to the printer.)
As an E-book format, it kind of blows- Most of my technical manuals are in PDF format, and they are a pain in the butt to read on anything but a proper computer or notebook. (THis includes smartphones- I'm still reeling from looking at a PDF on my shiny new 'droid.)
PDF kinda sucks.
It's actually PostScript with a funny tasting shell wrapped around it, which Adobe invented for printers and typography to get around the same problem. (allowing multiple platforms to send data to a printer and have consistent results regardless of who sent the data to the printer.)
As an E-book format, it kind of blows- Most of my technical manuals are in PDF format, and they are a pain in the butt to read on anything but a proper computer or notebook. (THis includes smartphones- I'm still reeling from looking at a PDF on my shiny new 'droid.)