I have had questions from customers on what comes extra within our EM Grid Control offering above and beyond our EM FMW Control.
EM FMW Control 11g is for managing and monitoring one single FMW Farm/ WLS Domain. If your topology comprises of multiple FMW Farms/Weblogic domains, you cannot use a single FMW Control to manage all of them at one place.
This is where EM GC 11g adss value. Apart from being a single management and monitoring portal for several FMW farms, EM GC 11g also allows you to monitor and manage non-middleware software such as OS resources, JVM, Database. With access to much more metrics than the EM FMW Control, it adds more value in Diagnosability and End to End Visibility.
Please refer to this link for details.