You're kidding right??It's impossible that you know nothing about it, just after signing up you can already see a message that the verification message was sent through email, all you have to do is to read and click the link, Do you even know how to read or you're just posting these threads just to add it up to your post count? - Just like what spammers usually do..
Actually you are taking him wrong, he is saying something else. The verification thing that you are saying is very simple and everyone making account on any social network needs to verify it but he is asking about specific users whose profile has a blue confirmation tag written "verified account".
I never look deep into it but as much I know it is the verification Twitter do manually and those account with verification tag always belongs to some celebrity. So here is the thing, I have seen some accounts with celebrity name but not verification tag so that might be fake accounts.
You can Google it or check it but I can assure you the thread was genuine