Private Automatic Branch Exchange (PABX) is a private telephone network used by organizations to facilitate communication among employees, both within the organization and with external parties. It operates as an in-house automated telephone switching system that connects multiple telephone lines to various extensions within the organization.

Key features and functionalities of PABX include:

Call Routing: PABX allows for intelligent call routing, enabling efficient handling of incoming and outgoing calls within the organization.

Internal Communication: Employees can communicate with each other using extension numbers, enhancing internal communication and collaboration.

External Communication: PABX also enables communication with external entities, including clients, customers, and partners, by connecting to the public telephone network.

Cost Efficiency: By utilizing PABX, organizations can manage their telecommunication costs more effectively, especially for internal calls.

PABX systems have evolved over time and often incorporate digital and internet-based technologies to provide a broader range of communication features, including voicemail, call forwarding, conferencing, and more. They are an essential tool for businesses to manage their communication needs efficiently.