number of hard drives on a network
 

How do we find the number of hard drives that are on a network. for example. if i do the command df -lk i get the following table.

/dev/dsk/c0t2d0s3 2030279 1734124 235247 89% /pkg3
/dev/dsk/c0t2d0s0 2030279 1285405 683966 66% /pkg2
/dev/dsk/c0t3d0s0 4124422 3244006 839172 80% /pkg1

note that i am connected to a network...
in this table if you look at the 3rd column you will find c0t2d0s3, c0t2d0s0 and c0t3d0s0 from these can we find out how many physical hard drives are there, could some one explain to me what is c , t , d , s stand for??? how it works please reply
there fily systems are on the same hard drive or different hard drive. how do we know that
ciao