3 party calling lets you conference multiple calls into a single call, so everyone can talk together.
When your working in a group or talking with family and friends it's often desirable for more than two people to be involved in a discussion.
When you have simultaneous calls it's possible to bridge them together so everyone can join in, this is known as 3 party calling or call conferencing. The phone initiating the 3-party call will need to have support for this feature.
* Feature requires phone support