#HAsh Tags#

                      #Hashtag . . .

Courtsey:Unhappy Ghost

A hashtag is a word or a phrase prefixed with the symbol #.[1][2] It is a form of metadata tag. Short messages on microblogging social networking services such as Twitter, Tout, identi.ca, Tumblr, Instagram, Flickr, Google+ or Facebook may be tagged by putting "#" before important words, as in:
#Wikipedia is an #encyclopedia that anyone can edit.
Hashtags provide a means of grouping such messages, since one can search for the hashtag and get the set of messages that contain it.

Hashtags first appeared and were used within IRC networks to label groups and topics.[citation needed] They are also used to mark individual messages as relevant to a particular group, and to mark individual messages as belonging to a particular topic or "channel". Generally, channels or topics that are available across an entire IRC network are prepended with a hash symbol # (as opposed to those local to a server, which use an ampersand '&').[citation needed] Hashtags' popularity grew concurrently with the rise and popularity of Twitter. It inspired Chris Messina to propose a similar system to be used on Twitter to tag topics of interest on the microblogging network.[3] He posted the first hashtag on Twitter:

“ how do you feel about using # (pound) for groups. As in #barcamp [msg]? ”

—Chris Messina, ("factoryjoe"), August 23, 2007[4]

The first high-profile application of the hashtag was by San Diego, California resident Nate Ritter,[5] who included #sandiegofire in his frequent posts on the October 2007 California wildfires hitting San Diego County. Internationally, the hashtag became a practice of writing style for Twitter posts during the 2009–2010 Iranian election protests, as both English and Persian-language hashtags became useful for Twitter users inside and outside of Iran.

The first use of the term "hash tag" was in a blog post by Stowe Boyd, Hash Tags = Twitter Groupings,on 26 August 2007, according to lexicographer Ben Zimmer, chair of the American Dialect Society's New Words Committee.

Beginning July 1, 2009, Twitter began to hyperlink all hashtags in tweets to Twitter search results for the hashtagged word (and for the standard spelling of commonly misspelled words). In 2010, Twitter introduced "Trending Topics" on the Twitter front page, displaying hashtags that are rapidly becoming popular.