**3. Internet of things**

A heterogeneous network of smart devices that are connected and communicated for transferring a large amount of data to provide services according to client application's requirements technically called IoT. To make the physical structures, such as buildings, transportation vehicles, transportation networks, information technology networks more smart, secure, and automated, IoT is a great solution. It can make the physical devices interact with each other. It divides the whole network into three main abstract levels, sensing layer, network layer, the application layer. **Figure 2** illustrates the working principles of IoT with detailed descriptions of all layers.
