Final answer:
In IoT, the characteristic describing different hardware platforms and networks is known as heterogeneity. It highlights the diversity of devices and communication standards in the IoT ecosystem.
Step-by-step explanation:
In the context of the Internet of Things (IoT), the characteristic where devices have different hardware platforms and networks is known as heterogeneity. This term refers to the diversity and variety of devices, protocols, and standards that are used within IoT ecosystems. IoT devices can range from simple sensors to complex industrial machines, each with its own hardware specifications and communication protocols. The fact that these devices need to interact and work cohesively is a major consideration in IoT design and poses unique challenges, particularly in the integration and management of the various systems.