Can someone tell me what a PBX is?
To explain PBX (Private Branch Exchange) technology, it might help to go back in time. You’ve probably seen the image of – or had first-hand experience with – the old-fashioned telephone operator answering phones in front of a large board, and manually plugging lines into different switches to connect the calls. This was the original PBX. Today’s systems essentially perform the same task without the need of manual switching.