John McCarthy, widely recognized as one of the godfathers of AI, defined it as "the science and engineering of making intelligent machines." In 1959, Arthur Samuel, one of the pioneers of machine learning, defined machine learning as a "field of study that gives computers the ability to learn without being explicitly programmed." Machine-learning programs, in a sense, adjust themselves in response to the data they're exposed to (like a child that is born knowing nothing adjusts its understanding of the world in response to experience). Nowadays, what 21st century digital technology generation need is computer system able to perform tasks that normally require human intelligence, such as visual perception, speech recognition, decision-making, and translation between languages. Machine learning is a subset of AI, which is an umbrella term for any computer program that does something smart. Natural languages are those languages that are spoken by the people. It is difficult for an individual to know and understand all the languages of the world. Machine translation (MT) is the task of automatically translating a text from one natural language into another.