Chatbot is a program for sending automatic responses to users' questions. Replies are close to the real-life dialogs and correspond to the essence of the question. Chatbots like this are used for giving feedback and performing different functions for the customer on websites, social networks, messengers, call centers, etc. Sometimes they also play the role of personal assistants (for example, Siri, Cortana and Alice).
Chatbots can be built on the base of artificial intelligence using machine learning (improving its understanding of human language in the communication process) or on programmed scenarios with the possibility to choose different options for responses or questions (algorithm).
How smart a chatbot is, depends on how it was designed. Chatbots with machine learning handle tasks better, all because they can understand human language. It learns to communicate with the user, gains experience and can solve new problems similar to the previous ones. In comparison to chatbots on programmed scenarios, the customer does not have to write specific phrases to receive a relevant reply.
The popularity of chatbots is caused by their economic profitability, the possibility to provide feedback 24/7 and the effectiveness of communication with customers, in particular, due to the possibility to provide quality service in two languages.