How does twitter work?

[Iratenest048]

I was just wondering about sending messages to people. I don't have a twitter myself but when you look at someones twitter and a tweet has someone else's name at the start is that from that person or to the person who's twitter you're on?
So who is sending the message to who?

[Smeagle x O.o]

It means the person is sending an ' at reply ' to them, so it's like a message.

[Kenny]

The @ is from the person sending the message. The @name is included as part of the message length and twitter only allows 140 characters, so the longer the name, the less room left for a message.