Testing the Call Waiting feature on Android. If you have it enabled, here is how you can hold a call, answer on a second line, swap calls, merge them into conference and slit if you need.
In this video:
00:02 The first incoming call from an unknown number.
00:11 Answering.
00:15 The second incoming call from a contact.
00:27 Putting the first one on hold and answering the call that is waiting.
00:36 Swapping from one to another.
00:53 Merging into the conference.
01:04 Splitting.
01:12 Dropping one call.
01:15 Hanging up.