Artificial Intelligence (AI) is a broad field that encompasses many sub-disciplines, including machine learning (ML).
AI refers to the simulation of human intelligence in software programmed to think and learn like humans. It aims to perform tasks that typically require human intelligence, such as understanding natural language, recognizing objects and images and making decisions.
Machine learning is a subset of AI that applies algorithms and statistical models to software (that may help optimize electro-mechanical systems) to automatically improve performance with experience. Machine learning is used to build models and make predictions or decisions without being explicitly programmed to perform the task.