Natural Language Processing (NLP) falls under the fields of computer science, linguistics, and artificial intelligence. NLP deals with how computers understand, process, and manipulate human languages. It can involve things like interpreting the semantic meaning of language, translating between human languages, or recognizing patterns in human languages. It makes use of statistical methods, machine learning, neural networks and text mining.
Google Translate uses some of the most advanced NLP tools available. Automated Chatbots, text predictors, and speech to text applications also use forms of NLP.
There are a number of open source libraries for NLP, including Natural Language Toolkit (NLTK) or PyTorch-NLP for Python and OpenNLP or Quanteda for R.
The introduction to this article provides a good overview of the background and techniques for NLP in a biomedical context: Harrison, C.J., Sidey-Gibbons, C.J. Machine learning in medicine: a practical introduction to natural language processing. BMC Med Res Methodol 21, 158 (2021). https://doi.org/10.1186/s12874-021-01347-1
The following articles each provide a clear, concise introduction to NLP: