What does message send failure mean on iPhone?

I sent this person a iMessage and it didn't go through and said "message send failure". I've texted this person before and had no problems but now it's saying this. The person I'm texting also has an iPhone. What does "message send failure" mean? Could it mean that there phone is off?

It means the text message didn't go through. You might be in an area with a really bad signal

It ether means you have no internet and in that case you can resend the SMS message latter. It also may mean the number is not a verified iMessage number.

How do i make a new one then

It's annoying