Whatsapp has introduced a new feature for video calling in which maximum four people can chat simultaneously. If a person do video call to other person an add participant option will occur on top right on both mobiles.Anyone can add participant that they want to include on chat.The main thing is whatsapp calls are end to end encrypted.This is very complex thing to achieve as telegram the famous messaging app even do not able to encrypt the group calls end to end.
Enjoy this new feature of whatsapp !!!!