The tag is a label, the end of a rope in the literal translation from English. English-speaking programmers put into practice this word in "message subject" value. Thus, tags are tails in the sea of text information, having pulled for the necessary tail it is possible to pull out required text contents easily.
It is possible to call tags heritage of subject library catalogs. They actually serve the same purposes as their predecessors from a pre-computer era: help to be guided with ease in a huge number of information. They represent short, put in two-three words or a phrase, the description of an essence, subject of any publication on the Internet – the text, video, the photo.
In modern virtual space it is already impossible to do without tags. The news websites, for example, exist many years, at the same time are updated several times in day, I turn in the enormous sizes a chaotic congestion of various information. Classify the maintenance of such websites in different ways, most often by authors of publications, but readers of a column of news are interested in a news essence, but not individual style of the author more often.
Besides, on the same subject different correspondents can write. Therefore it is the most convenient to resort to the help of thematic classification to find all notes relating to any incident it is not dependent on the one who and when published them. In recent years on many similar websites such text classification is obligatory, and for bigger orderliness there are fixed lists of tags, the author should select only from them suitable for the publication. Reasonably put down tags considerably facilitate to readers search of information interesting them, and to authors add popularity, the more simply there is a text, the more people will read it.
For convenience of users there is so-called "tag cloud". It is also the list where the most widespread, popular tags used on the website are displayed. It is called "cloud" because often visually reminds the image of a cloud. The more often texts of the website are marked with some certain tag, the more there is a font by which this tag is written in "cloud". By means of such simple, but effective reception, "tag cloud" becomes one of the most convenient instruments of navigation within the website.
In social (differently collective) open servers each user can think out own tags. In some of them through identical tags photos and records of different users can integrate. In others there is a so-called "search by interests" that in fact the same tags, they only characterize not one text or one photo, and all maintenance of a personal page. Using these opportunities, various people can find new acquaintances with whom they are integrated by any general interest: whether it be numismatics or love for parachute jumps.
Tags are necessary to classify information of any kind by sense.