PBX

A Private Branch Exchange (PBX) is a private telephone system used within an organization to manage internal and external calls. It handles call routing, extensions, voicemail, conferencing, and other telephony features without requiring a separate phone line for every user.

Traditional PBX systems were hardware-based and connected to the PSTN via analog or ISDN lines. Modern deployments have evolved to IP PBX (using VoIP) and Cloud PBX (fully hosted), dramatically reducing cost and complexity.