Samanthi,
Interoperability is a _big_ concept. Maybe one can appreciate it better when it's contrasted with code portability, which used to be, not too long, a noble idea.
Analysts see Java EE dying in an SOA world -
"The goal of the virtual machine is to provide for code portability, while in SOA, interoperability is far more important," he said. "Why go through all that trouble to build portable code, when in SOA, you want to leave the code where it is? Fundamentally, the virtual machine approach to distributed computing is through the serialization of objects leading to remote method invocation, while SOA runs on the exchange of messages between services with contracted interfaces."
Regards,
Dan