Which technology can understand what words really mean?

Natural language understanding (NLU) is a subset of natural language processing (NLP), a technology that enables computers to extract information from human speech or text. While NLP can analyse the structure of a set of words, NLU aims to provide insight into what those words actually mean. Of course, doing this well is difficult. There are problems with slang, irony, different syntax and, especially in spoken language, fragmentary phrasing. In fact, it is known as an "AI-hard" problem – one which, if solved by artificial intelligence, would put computers on the way to being as intelligent as people.