Looking for strong whitelist software or "reverse filters"

Hi all,

I'm new to the website and am looking for software that blocks all websites except the ones you want. I'm told that there are filters out there called "reverse filters" that do just that. I've also heard of whitelists that help with this too.

But I really need a program or software or DNS (I don't understand the tech jargon) that blocks all websites except the ones you allow and to have it password protected so that my accountability partner can be in possession of that. And if it can block webpages based on keywords that you use to search in online search engines that would be huge too. If any of you guys can help with this I would greatly appreciate it. Thanks!