The most important thing to know in an emergency (for both the caller and the call-taker) is where the emergency is taking place. With a location, the Sherborn Police Department can at least start a response, and call in, or call off other units/departments as is necessary.
Say you're talking to a friend from across town on the phone, and they tell you they are having chest pain, then the line goes silent. You dial 911 and tell the officer your friend is having a heart attack. The information displayed at the Sherborn Police Department is the information associated with the phone YOU are calling from. Knowing the address of the emergency saves valuable time in an emergency, and greatly increases the response time of rescue personnel.