What happens when you block someone on an iPhone 6, and they text you or call you?

Specifically, does the phone keep ringing or does it say the call can't be made? Does the text deliver and just never show up on the receiving phone, or does the sender get a message saying the text can't be sent?
(The other phone is not an iPhone.)

You never receive it, it doesn't matter what phone they have. No, to them it looks like the message was sent, thats it.

What is the meaning of the message "voicemail is not working. Try your call again later?"