The Internet of Things (IoT) marks a major shift in communication as it enables physical devices to generate, transmit, and share information independently. IoT applications are being developed to perform various tasks that allow devices to operate without human intervention. This change is necessary to increase user comfort, efficiency, and automation. However, creating this robust environment requires security and privacy, such as strong authentication mechanisms and effective recovery strategies to mitigate the threat. Significant changes are needed in the design of IoT applications to ensure the sustainability of the IOT ecosystem. This article will take an in depth loot at the security risks and threat sources associated with IOT Applications. Based on the analysis, it examines the different technologies developed to build trust in IOT systems. The article focuses specifically on the impact of IoT devices and machine learning role to enhanced security.