Plain English Meaning
The FAA group that creates and updates the official charts, approach plates, and airport diagrams pilots use. When you look at an FAA instrument chart or airport diagram, the information on it came from this office.
Full Definition
Aeronautical Information Services (AIS) is the FAA office responsible for collecting, maintaining, and publishing the official aeronautical information used by pilots, including instrument approach procedures, departure procedures, arrival procedures, airport diagrams, and the data shown on FAA charts. It is the authoritative source for the published procedures and chart products that flight crews rely on for instrument flight.