In a non-technical article Roger Chua explains that natural language processing (NLP) is an area of machine learning focused on teaching computers to understand natural human language better. NLP draws on research from AI, but also from linguistics, mathematics, psychology, and other fields. NLP enables computer programs to understand unstructured data, to make inferences and provide context to language, just a human brain does. For more see A simple way to explain Natural Language Processing (NLP).
For more, see A simple way to explain Natural Language Processing (NLP)