Now a day, the Internet of things are become a most essential component of the human life. This important role to extensive growth of world. To become a smart, update and give the less human interaction for doing task which save our time. IoT is everywhere, Internet of Things changing the way of human living because is a portable, wearable, implantable, making a worldwide and linked universe, and converting physical things that surround us into an environment to the information. This research paper presents a comparative analysis of various IoT simulator, their working behavior. The paper goal is to study of the existing simulation technique to make enhancement in the IoT device system performance, enhance security, testing of theories, their modeling methods. This paper also present the IoT architecture and their domains, Device of IoT, Types of IoT communications and challenges with existing prospective and scenario.