Named Entity Recognition

Named Entity Recognition (NER) is a fundamental information extraction task that finds and categorizes specific entities mentioned in text. For example, in "Apple CEO Tim Cook announced a new product in Cupertino," NER identifies "Apple" as an organization, "Tim Cook" as a person, and "Cupertino" as a location. Traditional approaches used conditional random fields (CRFs) and handcrafted features, but modern NER systems use transformer-based models fine-tuned on annotated datasets. NER is a critical component in knowledge graph construction, search engines, question answering, and document processing. Domain-specific NER (identifying drug names in medical texts or financial entities in SEC filings) requires specialized training data but provides enormous value for enterprise applications.