Wireless Sensor Networks (WSNs) find a wide range of acceptance and adoration in the current modern era due to the presence of self-configured autonomous sensors. In this chapter, first of all, we have advocated an overview of IoT-enabled wireless sensor systems while discussing the types of wireless networks. Afterwards, we have detailed the types of wireless networks with an in-depth background study while collaborating on characteristics of sensors, sensor architecture, and communication. This paper further emphasizes various kinds of sensors, sensing, and how data acquisition prevails so that remote users can easily engage with connected multimedia equipment owing to the Internet of Things (IoT), a basic virtual network. However, as data transmission is multi-layered, IoT adoption is fraught with difficulties despite its many benefits. Since flaws at any level potentially jeopardize the entire network, ensuring these layers are securely protected is one of the most urgent issues. Despite the fact that numerous researchers have examined security measures, the majority concentrate on specific methods, leaving significant gaps in the treatment of comprehensive IoT security. This study offers a thorough examination of WSNs, examining their unique characteristics, structures, communication methods, threats, vulnerabilities and range of uses. Further, we have collaborated the roles of Machine Learning (ML), Artificial Intelligence (AI) and blockchains for ensuring IoT security while discussing on the future perspectives of IoT security.