A conference call is a telephone call where the calling party wants to have more than one called party listen in to the audio portion of the call. The conference call may be designed to allow the called party to also talk during the call, or the call may be set up so that the called party merely listens into the call but cannot speak.

Some conference calls are set up where the calling party calls the other participants and adds them to the call, and in some cases the other participants call into the conference call, either by dialing into a "conference bridge", a specialized type of telephone that answers multiple calls, or by using a special telephone number set up for that purpose.

Conference calls can be used for entertainment or for social purposes, such as the party line. People call in to a specified telephone number which allows them to talk to others, serving as a way to talk to and perhaps subsequently meet new people. Conference calls are most commonly used by businesses.

The idea for conference call is widely used by some businesses throughout the world for the purpose of having virtual meetings, and for that, conferencing equipment is usually built by multiple manufacturers. Speaking of businesses, a conference call in this sense is actually hosted by certain companies in order to discuss the quarterly earnings, for instance, as well as the recent development or improvements in their line of business.

Aside from that, it is a usual circumstance during the course of certain types of conference calls that the institutional investors and analysts are given the chance to ask questions directly to the top management. On the other hand, during a conference call most of the individual investors may only be permitted to listen in; however, they are normally not given the opportunity to participate in the question and answer session.

Conference calling basically has three different types, and these involve the Dial-In Conference Call, Dial-Out Conference Call, and the combination of the two. It is noted that the Dial-In type is when all proposed participants of a conference dial-in into a given telephone number at an assigned date and time, then enter their PIN codes and obtain entry into the conference.

The Dial-Out type, on the other hand takes place when a certain operator dials-out the telephone numbers of all the proposed participants of a conference at an assigned date and time. In this type of conference call, the operator not only dials-out the numbers of the participants but also facilitates their induction in to the conference.

Finally, the combination of the dial-in and dial-out conference calls is noted as a conference call service in which some of the proposed participants of a conference dial-in to a provided telephone number at an assigned date and time, then enter their PIN codes and obtain entry into the conference. The combination of the first two types came about when, concurrently, the rest of the proposed participants of the intended conference call are dialed-out by an operator hosting the conference call and in the end inducted into the conference.