The act of getting 3 or more parties involved on a telephone call at the same time using a conference bridge to enable everyone connection on the same call.
See the following types of conference calling: On-the-Fly Conferences Always-On Conferencing Scheduled Conferences
Orange service allowing calls between up to six parties at any one time. You can unblock call barring and access international or premium rate numbers.
Most major service providers can accommodate up to three parties on the same call. Watch out, though. In most cases, airtime charges apply to each party on the call.
Conference calling definition
A calling plan feature that lets you talk with two or more people at the same time.