The Internet of Things, or the IoT, is the technology behind product-service systems. Like an iceberg, the physical ‘Things’ are the tip, visible above water while most of the technology and complexity is hidden, immersed under water. In this series of seven small videos, we will shed light on this digital technology, mapping its literacy through a layered framework so-called ‘stack’. We will explore what is the Internet of Things, extracting key roles of designers in the development of product-service systems.