A conference bridge allows a group of people to participate in a phone call. The most common form of bridge allows participants to dial into a virtual meeting room from their own phone.
This is in contrast to three-way calling, a standard feature of most phone systems that only allows a total of three participants. For most phone systems, conference bridging is an add-on feature that can be very pricey.
Conferencing is the core of collaboration and enables distributed or virtual teams. Combined with VoIP connectivity for remote workers, conferencing makes it simple and affordable for a team to function across a diverse geography.