Hi Wagawab! So the standard version is a mildly compressed but digitally optimal version of the PDF, in which the images are at a clear resolution and standard PCs or laptops with good drivers can navigate without much issue. The compressed version has much lower resolution on its images and assets, but is optimal for users with lower functioning devices such as most laptops and mobile users for navigability. The print version is a 300 dpi full resolution document, not meant for reading digitally as it puts a lot of strain on your computer, but rather is the standard resolution required for printing shops to print out the pages if someone would like to do so for personal use (although I would wait until I get the 3.1 out to print it out, I should probably remove it from the page for now).