According to Wikipedia, Natural language understanding “is a subtopic of natural language processing in artificial intelligence that deals with machine reading comprehension“.
Also according to Wikipedia, Oren Etzioni “coined the term machine reading” [Allen & Etzioni, 2013: From Star Trek to Siri: How the Machine-Reading Revolution will dictate the future].
The original DARPA “Machine Reading Program” (circa 2010) has subsequently been renamed “Probabilistic Programming for Advanced Machine Learning” — which to me is a strong indication that machine reading requires both probabilistic programmingand advanced machine learning….
See also my Quora answers to: