The prime advantage of a natural language interface, as opposed to the traditional point-and-click, or touchscreen, is the potentially unlimited flexibility of the instruction space using the textbox.
These tasks include, but are not limited to Enterprise Information Retrieval, Question Answering, Dialog-Based Search, Retail Transaction Processing, Event RSVP, Appointment Scheduling, Messaging etc.
Natural Language Processing (NLP) refers to AI method of communicating with an intelligent systems using a natural language such as English. The field of NLP involves making computers to perform useful tasks with the natural languages humans use.
Artificial Intelligence is the theory and development of computer systems able to perform tasks normally requiring human intelligence, such as visual perception, speech recognition, decision-making, and translation between languages.