What is the key function of a PBX system?

A PBX system, or Private Branch Exchange, primarily serves the function of routing calls both internally within an organization and externally to the outside world. This is critical for managing business communications, allowing employees to connect with each other via internal extensions without going through the public telephone network. Additionally, when calls need to be made to or received from outside, the PBX facilitates this by managing those external connections, ensuring efficient call handling and routing based on the organization's needs.

The routing capabilities of a PBX also include features such as call forwarding, voicemail, and automated attendants, which streamline communication processes within the organization. By centralizing call management, a PBX system enhances efficiency and productivity, allowing for better customer service and internal responsiveness.

The other options, while related to business operations, do not encapsulate the primary role of a PBX. Managing customer relationships falls within CRM systems, providing internet connectivity pertains to networking equipment, and storing voicemail messages is a feature rather than the central purpose of a PBX.