The Internet of Things (IoT) has been considered by industries and research communities as an important element for wireless communications. It covers a wide range of applications, from telecommunications to the creation of smart communities, which improve many aspects of our daily lives. Internet of Things is powered by the latest advances in smart sensors, RFID, communication technologies and Internet protocols. This thesis provides an overview of the Internet of Things (IoT) according to application issues, enabling technologies and protocols. The following is an overview of some of the main challenges of the Internet of Things. The relationship between the Internet of Things and big data analytics and cloud computing and fog are also considered.