Human-robot interaction is the study of interactions between humans and robots. It is often referred to as HRI by researchers. Human-robot interaction is a multidisciplinary field with contributions from human-computer interaction, artificial intelligence, robotics, natural language understanding, design, and social sciences. Human-Robot Interaction (HRI) is an advanced stream that has been grabbing a lot of attention over the past few years due to the increase in availability of complex robots and people's exposure to such robots in their daily lives, e.g. as robotic toys or, to some extent, as household appliances (robotic vacuum cleaners or lawn movers). Nowadays robots have been used vastly for real-world applications such as robots in rehabilitation, eldercare, robot-assisted therapy and in educational applications. Due to the advancement in AI, the research is concentrating not only towards the safest physical interaction but also on a socially correct interaction, dependent on cultural criteria. The aim is to create an intuitive, and easy communication with the robot through speech, gestures, and facial expressions.