Meaning – The term private branch exchange, refers to an automatic or manual private telephone exchange for transmission of calls to and from the public telephone network.
It also refers to a switching system located on a customeri?s premises that consolidate the number of inside lines (extensions) into a smaller number of outside lines (trunks). Many PBXs also provide advanced voice and data communication features.
In contrast to a public switched telephone network (PSTN), the main purpose of a PBX is to save the cost of requiring a line for each user to the telephone company’s central office.
Example of usage – “Traditional PBX phone systems use landline copper-based telephone lines that enter a business’s premises, where they are connected to a PBX box. That box contains telephony switches that enable calls to be distributed to different phones in an office and those phones to access a limited number of outside lines – trunk lines.”