Facebook is very widely used social networking site which is used by people all over the world.It introduced messenger for sending messages.
The app is very large in size so takes more memory in phone.And after we open the app it takes more time to connect even tough we have good internet connection.
It donot deliver messages quickly to other person even when he is online.The video calling quality is not good.
It also uses more data while we use app.
watsapp is very much better than measenger.