The document provides an overview of sensor-cloud architectures, applications, and issues. It discusses three main sensor-cloud architectures: (1) WSN-cloud computing platform that connects wireless sensor networks to cloud infrastructure, (2) a sensor-cloud architecture with virtualization that decouples real sensors from virtual sensors in the cloud, and (3) a data-centric sensor-cloud infrastructure framework. It also outlines the key entities and components involved in sensor-cloud integration like sensor owners, administrators, users, portal servers, and monitoring servers. Finally, it examines applications of sensor-cloud like healthcare and issues around security, energy efficiency, and virtualization.