Most large offices and institutions (and many small ones) employ a Receptionist to receive and give information to the people who call. It's the Receptionist's job to determine the nature of each caller's business and then direct him or her to those in the organization who may be able to help him or her. Most receptionist (particularly in small offices) have time when they are not occupied with callers. They may then handle other office tasks. Many receive and route telephone inquiries to the proper company officials. Receptionist who work for large establishments usually refer each caller to the appropriate company employee or official or else contacts his or her office by telephone and arranges for an appointment.
It's the Receptionist's job to act as her or his employer's public representative. To perform her or his job effectively, the Receptionist has acquired a thorough understanding of how her or his employer's business is organized.