A conference call is a telephone call in which three or more people converse simultaneously. Many companies use conference calls as a meeting tool or to distribute information to a large number of listeners at the same time. The two main types are MeetMe conferencing, in which each participant dials one number, and ad hoc conferencing, in which a moderator calls each participant.
Conference calls connect people through a conference bridge, which is essentially a server that acts like a telephone and can answer multiple calls simultaneously. Software plays a large role in whether the bridge has capabilities beyond simply connecting multiple callers.
A company can have its own bridge or can contract with a service provider for conference call hosting. Providers frequently offer add-on features for conference calls, such as attendee polling, call recording and in-call operators or attendants.
Companies using Voice over IP (VoIP) telephones can also host conference calls themselves if the VoIP software supports them.
Many phone conferencing systems require a login and personal identification number (PIN) to access the system. This helps protect confidential and proprietary information during the call.