how to restrict unwanted internet sites on fios router from childrens
It's called parental controls.
you will find it in the manual for your router make and model.
https://www.verizon.com/support/residential/internet/fiosinternet/networking/user+guides/user+guides.htm
Do keep in mind that using Parental Controls on the router can significantly decrease the performance of the router. It's better to use OpenDNS or commercial software on a computer, allowing the router to do the job it's good at.
