This is an example of a retweet by Apple's CEO, Tim Cook. We've taken the time to deconstruct and label each important part.
• Tweet = a max. 140-character message.
• Retweet (RT): Re-sharing someone else's tweet (like a Facebook Share). Generally, retweets are a sign of value.
• Feed: The stream of tweets you see on your page that is made up of the latest tweets from users you follow.
• Handle: Your username (twitter.com/handle).
• Mention (@): This is a way alert another user by using their handle in a tweet (e.g. @glasshattech). Users will be notified when they are mentioned.
• Direct Message (DM): A private, 140-character message between two people or a group. You can choose to adjust how you receive DMs via Security and privacy.
• Hashtag (#): This is just a way to let your followers know the topic of your tweet. You can also use hashtags to participate in a larger linked discussion (e.g. #iPhone6). This is a discovery tool that will allow users to find your tweets. This can be done by clicking on the hashtag to see all the tweets that mention it.
• Favourite: Favouriting a tweet will let the original poster know that you liked the tweet. You can do this by clicking on the star icon of a tweet (click on it again to undo). Generally, favourites are a sign of appreciation.