You can't find the answers to these Questinons just like that, you need to dig into it in the MSDN or some other sites

for example you can use the below link to gather some information on your first Question (Pagination in SSRS)

Generally logical pagination is used by the HTML and GDI rendering extensions and

physical pagination is used by the print control and the TIFF and PDF rendering extensions.

http://blogs.msdn.com/b/bwelcker/archive/2005/08/19/454043.aspx

instead of looking for answers start exploring 🙂