Paging
From Hackepedia
When a process causes a page fault because of missing data, this data is "paged in". When a process is forfeiting memory the data is "paged out" to swap, subsequently when this data is needed again it is "paged in" again. Paging is different from swapping because swapping moves the entire memory of a process to/from swap. Different architectures have different size of pages (pagesize):
i386: 4096 bytes
amd64: 4096 bytes
sparc: 4096 or 8192 bytes
sparc64: 8192 bytes
vax: 4096 bytes
alpha: 8192 bytes
macppc: 4096 bytes
mac68k: 4096 bytes
To find the pagesize of your system try typing "pagesize".
$ pagesize 4096