A slowly and gradually technological change has resulted in many aspects of our lives being connected and affected by modern communication. Millions and Billions of people connected to global system of interconnected computer networks today. According to a survey the number of connected devices will exceeds 50 billion by the year 2020. The internet of things I would say a major transformation in a modern day to day world that haveaffected everyone and business as well. The internet of things was defined by ITU (International Telecommunication Union). Internet of things has moved from being a futuristic vision from last year. Nowadays smart homes automation, smart water networks that connects our world. Normally a wireless sensor network is formed by large sensor workstations where each workstation or node having sensors that would detect heat, light etc. This paper will briefly explain the network security, cyber security, internet of things and wireless sensor networks.