Wifi router provides various useful setting and set password is common and mostly is aware with it. You can block certain MAC address and limit bandwidth for devices.
But when you are away from your home and in any error, you family does not know how to tackle then it is problem for them because you can solve it on phone call.
So you can access from any location in the world, if you have internet access. Read below to know more: –
Open setting page and find DDNS option and enable it, it will show you dyndns.org and no-ip.com in the dropdown list. You can choose any but you need to sign up for account and put these details in settings.
If you need further help then comment below, I will help you.