A variety of tasks NLP has been applied successfully
Information retrieval. The science of searching for relevant documents, finding specific information within them, and generating metadata as to their contents.
Information extraction. A type of information retrieval whose goal is to automatically extract structured information, such as categorized and contextually and semantically well-defined data form a certain domain, using unstructured machine-readable documents.
Named-entity recognition. Also known as entity identification and entity extraction, this subtask of information extraction seeks to locate and classify atomic elements in text into predefined categories, such as the names of percentages, and so on.
Question answering. The task of automatically answering a question posed in natural language; that is, producing a human-language answer when given a human-language question. To find the answer to a question, the computer program may use either a prestructured database or a collection of natural language documents (a text corpus such as the World Wide Web).