Which among below is an important architectural characteristic that describes the ability of one application to be able to communicate with another application on a different application platform ?

Interoperability is the ability of different systems or applications to work together and exchange information, even when they run on different platforms or are built by different vendors. This is a critical architectural characteristic for distributed systems and integration scenarios. Portability refers to running on different platforms, extensibility to adding features, scalability to handling growth, and serviceability to maintenance - none specifically address cross-platform communication.