Chatbot technology has experienced rapid growth in recent times, and these intelligent systems engage in real-time conversations with humans using natural language. Chatbots act as AI-powered entities which can simultaneously engage with numerous individuals, capable of providing instant responses. Virtual assistants are the common name for such programs. This paper aims to discuss chatbots’ classification, focusing on its design and implementation, also analyzing the techniques and models used for its development, and its utilization across diverse industries along the limitations of this technology by doing the comprehensive review and analysis of research papers published in various research journals through the years 2016 to 2020.