Natural Language Processing (NLP) is a field of computer science and artificial intelligence concerned with the interaction between computers and human (natural) language. NLP applications are software systems that use NLP techniques to process and analyze human language, such as speech and text.

Some of the most common NLP applications include:

1. Text classification: Software systems that categorize text into predefined categories, such as sentiment analysis, spam detection, and topic classification.
2. Named entity recognition (NER): Software systems that identify named entities, such as people, organizations, and locations, in text.
3. Text summarization: Software systems that condense large amounts of text into shorter, more concise summaries.
4. Question answering: Software systems that answer questions posed in natural language.
5. Machine translation: Software systems that translate text from one language to another.
6. Speech recognition: Software systems that transcribe spoken language into written text.
7. Text generation: Software systems that generate new text based on a given prompt or model.
8. Sentiment analysis: Software systems that analyze text and determine the sentiment expressed, such as positive, negative, or neutral.

These NLP applications are used in a wide range of industries, including customer service, marketing, finance, and healthcare. They can help organizations automate routine tasks, gain insights from large amounts of text data, and improve the customer experience.

In summary, NLP applications are software systems that use NLP techniques to process and analyze human language. They are used in a variety of industries and can help organizations automate routine tasks, gain insights from large amounts of text data, and improve the customer experience.