Yes, absolutely. I'm happy to answer that.
First of all with regard to DNS, the Internet works on a series of numbers and we go to www.website.com, but the Internet doesn't understand what that is. DNS translates back into the actual address on the Internet, which is called an IP address. So it tells the Internet how to route itself and how to get to the location.
Cybercrime actors take advantage of that, so when you click on a link, if you were going to impersonate the cyber centre, for example, you might create a domain or a website that would say “cyber.gcca”. You might miss the dot and so fool Canadians; they wouldn't see it—that's called “typo-squatting”—and then they would go to something that looks like the cyber centre website, except you're downloading malware when you're there.
So a DNS firewall says, hey, that's accidentally been blocked as an illegitimate site, so when you click, you don't go there. So it stops you from having the consequence of either the mistyped address or the deliberate....
In terms of my using these, I absolutely do. I put them on my personal devices because, frankly, it gives me a level of protection. I admit it's only a matter of time before something happens and I click. I want to make sure that I'm as protected at every level as I can be.