delta download of org model

hi experts,

we have done the initial download of org model from ECC 5.0 to CRM 5.0.

now we need to understand that is there a delta download available on the org model. if we do any changes in org model in either of the systems will it automatically get reflected into other system?

any specific settings/ configurations to be done to enable org model delta download?

please let us know your views at the earliest.

thanks in advance

RH