Attended Transfer: when a call is transferred to someone and the person on the phone talks to the receiving end and lets them know they are transferring a call to them and all the information they know.
Answer a call
press the transfer button
will show up as person transferring the call
dial the number
wait for someone to answer
then press the transfer button again
will show the original person calling number
Blind Transfer: when a call is transferred to another person and the sending person transfers and then hangs up once the transfer button is pressed.
Answer a call
press the transfer button
dial the number
press the transfer button again