Information and Communications Technology (ICT) controls our daily behaviors. It becomes a main part of our life critical infrastructure bringing interconnection of heterogeneous devices in different aspects. Personal computing, sensing, surveillance, smart homes, entertainment, transportation and video streaming are examples, to name a few. As a critical living entity, Internet is contentiously changing and evolving leading to emerging new technologies, applications, protocols and algorithms. Acceleration of wireless communication trends brings an ever growing innovation in Internet connectivity and mobile broadband. Infrastructureless communication devices become ubiquitous, smart, powerful, connectible, smaller, cheaper, and easier to deploy and install. This opens a new future direction in the society of ICT: the Internet of Things (IoT). Nowadays, the IoT, early defined as Machine-to-Machine (M2M) communications, becomes a key concern of ICT world and research communities. In this paper, we provide an overview study of the IoT paradigm, its concepts, principles and potential benefits. Specifically, we focus on the IoT major technologies, emerging protocols, and widespread applications. This overview can help those who start approaching the IoT world aiming to understand and participate to its development.