can anybody explain me the concepts
virtual memory mangement, swapping and paging?
although i roughly know what they are , i need
more solid distinction between them, and also i want to figure out
the relations between them?
do you have any well-defined definitons for this concepts?
The Paging Game, though venerable, is still the best explanation I've yet read of it. That it's funny is even better.
paging is managing RAM data by pages (nK chunks, called page size), swapping stores it temporarily on disk if it's not needed right away to extend physical memory through a technique called virtual memory management (VM). When the kernel moves data between RAM <-> CPU that is paging, and data moved between RAM <-> DISK is swapping.
[Actually, the memory management is usu. handled but a subprocessor component called the MMU, but for practical purposes, let's just say it's in the CPU package deal. 
]
Specific flavors of UNIX use slightly different techniques and tuning. Getting down to the nitty gritty is kernel tuning, which is one of the Black Arts of UNIX. For Solaris specifics, see Adrian Cockroft's book "Sun Performance and Tuning" (slightly outdated, but is considered the "bible" on Solaris tuning).
-Phrazz
See more here: Paging (Wiki)