AI is a broad term going back to 1955. It covers many different techniques, algorithms, and topics. The first AI chess programs (DeepBlue, et. al.) were using tree search algorithms like alpha-beta pruning that are/were classified as AI techniques.

Machine translation is a research topic in AI because translating from one language to another is something humans are good at while computers are not traditionally.

More recently, the machine learning (ML) branch of AI has become synonymous with AI as have the various image models and LLMs built on different ML architectures.