Natural Language Processing (NLP) is a field of Artificial Intelligence that focuses on the interaction between computers and human language. Applications such as Sentiment Analysis, Speech Recognition, and Spam Filtering in emails all involve NLP as they deal with analyzing, understanding, and processing human language in text or speech. However, Stock Market Analysis does not directly involve NLP, as it is more related to financial analysis and data modeling, though NLP may sometimes be applied for processing market-related news and reports.