Question regarding Install and Setup OEM 12.1.0.3

Gurus,

I am performing OEM 12c silent installation and came through below parameters in response file "new_install.rsp" regarding existing database hostname, listener port and service name. I am doing this for first time and confused about this existing "Repository Database".

#-------------------------------------------------------------------------------

#DATABASE_HOSTNAME :<String> Hostname of the Repository database.

#       Example    : DATABASE_HOSTNAME="hostname.domain.com"

#LISTENER_PORT:<String>  Port on which the Repository database is running.

#       Example    : LISTENER_PORT="1521"

#SERVICENAME_OR_SID:<String> SID or Service name  of the Repository database.

#       Example    : SERVICENAME_OR_SID="emrep"

#SYS_PASSWORD:<String> Password of DBA user used to create repository schema.