Twitter terminology: what do RT, MT, #FF, #, @ mean in the Twittersphere?

Twitter allows 140-characters messages. This is not much. Moreover, no good Tweet is 140-chars long because it’s impossible to share or reference. Over time, a special set of abbreviations and cropping techniques has been developed to help optimise the space. Click on read more to see a handy glossary of the most used Twitter terms and abbreviations.

Tweet

A Tweet is a message posted via Twitter. It contains max 140 characters.

DM (Direct Message)

These are private Tweets between the sender and recipient. When sent by SMS or a managing tool (like Hootsuite), DM must begin with "d username". It specifies it’s a DM and who the message is for.

Follow

To follow someone on Twitter is to subscribe to their Tweets or updates on the site

Mention

A user is mentioned in a Tweet when this includes a link to that user’s profile, written like this: @user (see also @). It is used to attribute some content, reply or call someone

@

The @ sign is used to call usernames in Tweets. “@user” is a link to the Twitter profile of “user”. See also Reply and Mention.

Reply

It’s the reply to another user's message and always begins with @username (referring to the user you are replying to)

# (Hashtag)

The # symbol is used to mark keywords or topics in a Tweet

RT (Retweet)

It is placed before the retweeted text when users retweet a message manually or with a managing tool. A Retweet is a Tweet by another user, forwarded by another user to his/her audience. It is used to spread news or share valuable content.

MT

Meaning “Modified Tweet”, it is similar to RT. It is used when a manually retweeted text has been modified (shortened or changed but still recognizable)

URL Shortener

A software used to shorten URLs to usually 20 characters

#FF

This hashtag, meaning "Follow Friday", is used on Fridays to suggest to other Twitter users who are worth following

Source:

Twitter