Three-way calling lets you initiate a conversation between you and two other callers at the same time. You can also use Google Hangouts to start a group conversation.
To start a three-way call:
From your phone, dial the first number. When the call is answered, press the Flash button on your phone to place the caller on hold.
Wait for a dial tone, and then dial the second number. When the second call is answered, press the Flash button on your phone again to connect all three callers.
To add a caller to a current call:
If you're already on a call and want to add another caller, press the Flash button on your phone to place the current caller on hold.
When you hear a dial tone, dial the number you want to add and wait for the caller to answer; then press Flash to connect all three callers.