Nowadays, one of the main objectives of Internet is its own development, so it can provide the potential of ultimate communication, not only among human beings but also the communication between humans and devices, as well as among devices (M2M), without the need of human interference. We enter an era, where Internet is everything, specifically, Internet of Things (IoT). Every object will have a unique identifier and will be able to locate itself and connect to the Internet. Radio Frequency Identification techniques will be the base of IoT. The book consists of three main themes. At first, is defined the meaning of IoT, is analyzed its architecture and development structure in connection with cloud computing and its services to users. At second, is presented the effective implementation of this emerging technology in a smart city. And at third part, the author concludes that this technology is still in a primary stage of development presenting deficiencies, risks and improvement potential.