Machine Learning is an application that is a subset of Artificial Intelligence.
Machine Learning is the process of using mathematical models created using past know outcomes to help a computer learn without direct instruction. As machine learning algorithms are used, they learn and improve based on the data and the outcomes.
AI is a broader term of many applications that does includes machine learning. AI is the “capability of a computer to replicate human cognitive functions”, such as learning and problem-solving. AI will simulate reasoning in the same way that a human does. AI includes applications like natural language processing (chat bots), autonomous vehicle technology, human like interaction in gaming etc.