IoT platforms provide tools and services to connect heterogeneous IoT devices, enable data flow and storage, and offer data analysis capabilities. They are scalable to handle billions of devices and messages per hour. Key features of IoT platforms include powerful data analytics and visualization dashboards, integration with other tools and platforms, and pay-as-you-go pricing models. Popular IoT platforms include Google Cloud Platform, Salesforce IoT Cloud, ThingWorx, IBM Watson IoT, Amazon AWS IoT Core, Microsoft Azure IoT Suite, Oracle IoT, and Cisco IoT Cloud Connect.