What is the usage of sys.sysrowsets

Hi,

I just wonder what is the usage of sys.sysrowsets in SQL Server? Microsoft said it
“Exists in every database. Contains a row for each partition
rowset for an index or a heap.” But what is a partition?

Also what is the meaning of idmajor and idminor for this
table? I try to find the object ID of a table(246486340)
and then execute the query:

Select * from sys.sysrowsets where idmajor
= 246486340

The results are two records:

rowsetid ownertype idmajor idminor numpart status fgidfs rcrows

72057603504865280 1
246486340 1 1 6 0 2582

72057603612213248 1 246486340 6 1 2 0 2582

But I think there should only
be one record with that major id.

Thanks

Please see http://www.sqlservercentral.com/Forums/Topic1730214-391-1.aspx