Call waiting option in Samsung j7

Normally when you are in a call and at the same moment if someone tries to call you they will get it as number busy. 
But in this situation you wouldn't know who called you while you are in another call. 

If you are using Samsung j7 you can easily put that second caller as waiting. 
So you can stop or hold the first caller and get the second caller. This facility is really helpful when you are getting so many calls. 
You can take most important calls while you are in another call. 

So when you are in a call if you get another call it will display second callers information. Here you can use hold option to the first caller.
All you need to do is follow these steps.

1.First go to call log.
2.Then click on menu bar.
3.Go to more settings
4.Then turn on call waiting