Regarding Virtual & physical DB hostname

Dear Experts

1. In Production,We have cluster services in UNIX, with 2 nodes CI & DB.

My query is regarding virtual & physical DB host name. when i checked from SYSTEM->STATUS->Database data->HOSt-> it's pointing to physical DBhostname BUT Rz10->default profile->parameter SAPDBHOST->pointing to virtual DBhostname.

Moreover , in some activities we use Physical name, for others use virtual name. For eg:

a) to shutdown database we use physical DB name

b) T-code-DB13, execute Jobs using virtual Db name

2) In quality & development server, i found physical & virtual name are same, no such disprencies...

Please help...