In the past, only the computers communicated with each other on the same network (internet) and there are a main computer called a Server that serves to the other computers. But now we see devices other than computers connected to the Internet such as Mobile, Smart wristwatches, Vehicles, Rockets, Washing machines, Refrigerators, Smart glasses, Medical devices and so on. So, we can simply describe the Internet of Things IoT as a many things (devices) connected to internet and the information is exchanged between them. There are main pillars of IoT Applications such as,

1. Smart Home Applications, their are include washing machines, refrigerators, stoves, smart lampshades, smart meters and so on.

2. Smart Industries and Cities Applications, First, Cities applications their are include controlling of light systems, remotely parking and  monitoring the temperature, humidity, wastes, noise level and traffic ..etc. Second, Industries applications their are include monitoring of factory operations, quantity of products, energy & resources consumption and safety & quality factors..etc.

 3. Medical Applications,  their are include an implanted devices inside the human body, organs transplantation and monitoring the body   organs conditions. In general, there are many healthcare applications such as  Follow up the patients conditions and monitoring the             medical devices status and their maintenance times..etc.

4. Mobility and Transportation Applications, now the cars, trains, bicycles, shoes, planes and any vehicles can connected to the internet and the information is exchanged between them.We can predict the errors and malfunctions of the vehicles. The vehicle sensors which embedded in On-Board Diagnostics Port can save vehicle data and transmit it (by carrier network like 3G, 4G, Satellites..etc) into the services center to maintain it. 

5. Infrastructure Applications, their are used in building management systems and monitoring the stability, leaning, load and tension of   building. Also, their can measure the power consumption , light intensity and air quality.