NLP (Natural Language Processing) is a subfield of machine learning that focuses on teaching machines to understand and generate human language. It involves developing algorithms and models that can process, analyze, and generate natural language data, such as text, speech, and other forms of communication.

NLP has numerous applications in various industries, such as chatbots, voice assistants, machine translation, sentiment analysis, and text classification, among others. Some common techniques used in NLP include text preprocessing, feature extraction, language modeling, sequence-to-sequence models, attention-based models, and transformer-based models like BERT and GPT.

NLP models and algorithms often require large amounts of labeled data for training, and they can be computationally intensive. However, recent advancements in deep learning have led to significant improvements in NLP models, allowing them to achieve state-of-the-art performance on various natural language tasks.