Why isn't my tweet message showing up on this person's page?

[mammothsheet535]

I am new to using twitter and not very familiar with how this site works, but I sent a tweet message to someone, and I noticed that my tweet is not showing up on their twitter page, and they have not responded back to my message. Does this mean that the person never received my tweet? Can someone please explain to me how twitter works because I am confused?

[kuljo]

don't know how tweet works but perhaps there is way to message