Businesses that need a dependable internal and external communication network must have Private Branch Exchange (PBX) systems. In addition to providing access to external communication channels like VoIP or PSTN, a PBX System links telephones within an enterprise. By using SIP trunking instead of analog phone lines, it enables companies to manage both internal and external conversations. An fully hosted PBX system, referred to as a hosted PBX or cloud PBX, is one that is hosted and managed by the service provider on the cloud. Modern business communication depends heavily on PBX systems, and knowing how they differ from one another aids in decision-making. While IP PBX delivers cost effectiveness and hosted PBX guarantees maximum flexibility, classic PBX gives stability.