The Internet of Things (IoT) has emerged as a transformative technology used in a wide variety of industries, right from healthcare and manufacturing to retail and smart homes. The IoT has evolved from a simple connectivity of a device with an on/off switch communicating information over the internet to an intricate smart ecosystem of interconnected devices. In this chapter, we will cover the evolution of IoT devices, starting with a humble beginning, present-day reality, and exciting future possibilities emerging as IoT gets integrated with artificial intelligence and machine learning. We look at several architectures for IoT systems and the support to be provided by each layer to create a seamless system. We will also look at the new and exciting applications and emerging use cases and the reasons for adopting this technology rapidly.