If you want to tell the new person about the caller’s issue and give any background information before transferring the call, you can choose attended transfer.
Scenario: You (B) are talking with A, then transfer the call to C.
During the call with person A, dial *2 on your phone.You will hear the prompt “transfer” and the dial tone.
Dial C’s number.C’s phone is ringing. After C answers the call, the call between you and C is established. In this time, the call between you and A is held.
Hang up your call, the call between A and C is established.