Watson is a question-answering computer system that IBM built to understand questions posed in natural language. The idea was conceived in 2004. In initial tests in 2006, David Ferrucci, senior manager of IBM's Semantic Analysis and Integration department, gave the system 500 clues from past Jeopardy! programs, and it answered only about 15% correctly. In 2007, Ferrucci's team at IBM's Watson Research Center in Yorktown Heights, New York, began developing Watson in an exploratory research project called DeepQA, with the goal of rivaling human Jeopardy! champions.

To respond within seconds, Watson ran many language-analysis and search algorithms in parallel, generating candidate answers and scoring the evidence for each. In February 2011, it competed on Jeopardy! against former champions Ken Jennings and Brad Rutter and won with $77,147, ahead of Jennings with $24,000 and Rutter with $21,600. IBM donated the $1 million first-place prize to charity. IBM then applied the technology to fields including medicine, finance and law.