The simulation of human intelligence in machines is known as artificial intelligence. A conversational AI-powered program is referred to as a chatbot. Rule-based systems, machine learning, natural language processing, and deep learning are employed in the creation of chatbots. It attempts to investigate the design strategies and methods employed in the construction of conversational chatbots with intelligence. In this paper, we give an outline of the components involved in building chatbots that can interact meaningfully with people. These elements include natural language generation, natural language understanding, and natural language dialogue management. The creation of personas, conversation flow, and user experience are all thoroughly discussed. The study also examines several chatbot-building methodologies, such as machine learning algorithms and dialogue management tools. The study outlines the benefits and drawbacks of various design strategies, offering information on their applicability and effects on chatbot functionality. Researchers and practitioners can make wise choices to create intelligent conversational chatbots that provide better user experiences by knowing these design methods and strategies. These chatbots will have conversational skills similar to humans.