A retweet in the microblogging service Twitter is the forwarding of a tweet from other users to one's own followers. Every tweet that can be seen in the timeline of your own profile can be forwarded by clicking on Retweet. Tweets of users or profiles with which there is no connection can also be retweeted, meaning that a tweet can go viral.
There are three ways to retweet on twitter.
With a manual retweet, you would firstly copy and paste the tween into your own tweet. The message would then be preceded by the abbreviation "RT", which stands for "ReTweet". After that follows with "@Username" a kind of author's name - instead of "Username" comes the user's username, which is quoted by the user. The indication of the author belongs to the social media etiquette - similar to references on websites or citations in the academic field.
Then the actual retweeted message follows. After specifying "RT" and the user name, it’s possible that the message might exceed the 280 characters in total, particularly if the original tweet already exhausted the word limit. In this case it might be necessary to shorten the tweet so that the copyright notice isn’t lost.
Twitter has subsequently integrated the function of automatic retweet. Below or next to a tweet there is a symbol with two arrows following each other – if a user uses this button, a retweet is generated automatically.
The difference to the manual retweet is that the specifications "RT" and "@Username" are not prefixed. In this variant, the full 280 characters of the message could therefore be used, and below the retweet, you see that it is a retweet and the author's name. However, this cannot be evaluated using the Twitter search function, as is possible with manual retweets. To do this, the original tweet displays who has automatically retweeted or forwarded the message to the original tweet.
Since the beginning of 2015, Twitter has offered a further function for retweeting. When you click on the Retweet button, a pop-up appears in which you can see the selected tweet and a comment field. This makes it easier for users to express opinions, thoughts or other statements about a particular tweet, without the space being limited to 140 characters minus copyright. Twitter also uses the microblogging principle: Only a small number of characters is always available
Depending on the constellation, retweets and information about them appear in different places.
Retweets are a much better indicator of the importance or information content of tweets than, for example, the number of followers that has long been regarded as a key figure for the success of a Twitter account. In a large follower crowd, there is often a high proportion of inactive users (e. g. accounts of movie and music stars) who either do not even read the tweets or at least do not interact with the author. If a message is frequently retweeted, it can be assumed that the information passed on is of importance to the users. Retweets are thus a measure of the actual interaction between users.
Regardless of the consequence relationship between users, retweets can be used as multipliers. If one of the retweeted users has a very large network, the range is increased enormously. In collaborations between social media sizes and companies, the Retweet function is often used to distribute advertising messages, product and brand recommendations with the greatest potential to go viral. Two Twitter networks are already able to make such contributions to a very large group of recipients. Some Twitter users therefore specifically ask for retweets. 
In some cases, this viral effect is exploited by bot profiles that automatically pass on the tweets of certain users. However, this should not be the case in business. Of course, this abuse also falsifies the degree of interaction. Twitter has introduced limits for such and other cases, which limit the number of daily retweets to 1000, for example.