The correct term is a Power User Interface (or sometimes an Expert-Oriented Interface).

These interfaces are optimized for efficiency and speed, not for ease of learning. They assume users are already familiar with the system, allowing fast command entry and minimal visual overhead.

Examples include command-line tools, airline reservation terminals, and advanced editors like Vim or Emacs.

🔹 Note: This is not the same as an Expert System, which refers to an AI system that simulates human expertise in a specific domain.