@Bob, what are these people doing?
https://twitter.com/brianvastag/status/620993700424867840
Is that retweeting, or are they sending a message to Brian and Director Collins? Or both?
I don't understand Twitter!
lol, you're on a steep learning curve here.
OK, so, underneath Brian's tweet are a list of responses from other people, where they've written their own messages. Those are individual tweets. If you reply to a tweet, then it gets sent out as an individual tweet but it also gets listed underneath the tweet that you are responding to. To reply to a tweet, there's a little text box just underneath the tweet, or you can click on the little curvy arrow icon at the bottom of the tweet (the first icon from the left) and a text box will appear.
If you look at all of the tweets listed underneath Brian's original tweet, they all start with Brian's Twitter tag... This is written into the tweet automatically when responding to a tweet. If someone's tag is included in your tweet it means that it will get sent to their alerts for their attention. Busy celebrities don't read most tweets directed to them because they are overwhelmed, but lesser mortals tend to read everything directed to them. (If you want your tweet to be seen by all your followers, then don't start it with a tag. If u start a tweet with a tag it will be mainly for the attention of the person tagged. It will still be public but not widely distributed.)
Where the nih director has been tagged, that means that the tweet will also be sent to his alerts. (But it doesn't mean he will necessarily read them.)
Now... It starts to get interesting... If you look just underneath Brian's tweet, on the left hand side, it says 'retweets' and 'favorites' and gives a number for each. That indicates how many times the tweet had been... Yes, you've guessed it... how many times it's been 'favourited' and 'retweeted'. If you click on the numbers indicating the number of retweets or favourites (where it says 'retweets' and 'favourites'), it opens a pop up box that gives you a full list of the people who have retweeted or favourited, except for any private accounts.
If you look at the avatars listed horizontally, just below the tweet, they give an indication of a small portion of the people who have retweeted. That's not very helpful really, but it looks pretty.
To favourite or retweet, click on the second and third icons, from the left, underneath the tweet. So, these are just to right of the 'reply/respond' icon that I mentioned above. The circular arrow symbol is to 'retweet', and the star symbol is to 'favourite'.
Hope that helps? Probably as clear as mud? You'll have a head ache by now.