This chapter describes some important highlights in the history of the IoT (Internet of things). Nowadays, the internet-based information architecture allows the exchange of services and goods between all elements, equipment and objects connected to the network. The IoT refers to the networked interconnection of those everyday objects, which are often equipped with some kind of intelligence. In this context, Internet can be also a platform for devices to communicate electronically and share information and specific data with the world around them. So, IoT can be seen as a real evolution of what we know as Internet by adding more extensive interconnectivity, a better perception of the information and more comprehensive smart services. For the most part, the Internet was used for connection-oriented application protocols like HTTP (Hypertext Transfer Protocol) and SMTP (Simple Mail Transfer Protocol). However, nowadays a large number of smart devices ommunicate between themselves and to other control systems. This concept is known as M2M (Machine-to-Machine communications).