how does twitter work?

[chiddy chiddy bang bang]

i always hear people say follow my on twitter at #username
but when i see twitter comment i kind of have a hard time understanding them . like example

"today i was at #ballpark watching a game with #adamsmith. had a great time thanks #74robert "

does that mean that (#ballpark ,#adamsmith , and #74robert ") since i included their username in the comment, the same comment will appear on their wall? or only those 3 username will be the only ones to be able to read it on my wall?
can i post a tweet on ssomebody elses account/ wall

[R.B. Lyn]

You're using the wrong symbol dear. The "#" you are using are called Hashtags and it's used to indicate a topic of a tweet. (It's your choice if you want to put one) With hashtags, people can see your tweets more if they click the hash tag. It automatically becomes a link and you'll see all of the people using the hash tag.

"@" This is what you use to mention a person on twitter. No, you can't post on someone's profile with a tweet, unless they RT or Retweeted you and that is when your tweet will be posted in their accounts.

If you mention 3 people at the same time, the 3 of them can read the tweet on their Mentions/Interaction panel.

Your tweet doesn't appear on their profile but on the Mentions/Interaction where you can see everything that has something to do with you. Like, "I'm with @[your usernam]" It will automatically appear there.

If you mention those 3 people - @Ballpark, @adamsmith, and @74robert, they can see their mentioned username on their Mention/Interactions as I've said earlier, but people can still read those tweets since people are following you. But if your twitter is private, only they can see the tweet and the people following you.

That's all. I hope you understand.

And, nope, you can't post a tweet on somebody's wall (Unless they retweet it)

Oh, and I forgot, if they retweet you (if you're profile is not private) the people following them can see your tweet. And if they retweeted your tweet, it will also appear on the wall and other people can see again your tweet. It's like a chain though

Hope that helped!