What happens if you block someone and they attempt to call or text you?

I have a Verizon 4s iphone. I recently got the ios7 update and it comes with an option to block contacts. What happens if I block my ex and he tries to call me? Text also? Will he be notified that I blocked him? Or what happens?

It will come up as if he called a non working number

I think it just goes to voicemail. And the text sends but you don't receive it.