Can someone please explain to me what hashtags on Twitter are used for!?!?

[Kathy Sparkle]

Okay, so I have no idea. I see them everywhere! I'm so confused. Please, can someone explain to me what they mean? I would very greatly appreciate that. Thank you in advance!

[Ali]

Hashtags Introduction 

Hashtags are a community-driven convention for adding additional context and metadata to your tweets. They're like tags on Flickr, only added inline to your post. You create a hashtag simply by prefixing a word with a hash symbol: #hashtag.

Hashtags were developed as a means to create "groupings" on Twitter, without having to change the basic service. The hash symbol is a convention borrowed primarily from IRC channels, and later from Jaiku's channels. 

hashtags.org provides real-time tracking of Twitter hashtags. Opt-in by following @hashtags to have your hashtags tracked.  Similarly, Twemes offers real-time tracking without the necessity of following a specific Twitter account.  Also, with their purchase of Summize, Twitter itself now offers some support of hashtags at their search engine: http://search.twitter.com. Other services such as TweetChat, TweetGrid, and Twitterfall are also popular for following hashtags in real-time.

 

How To Use Hashtags

Start using hashtags in your tweets, preceding key words. It can be helpful to do a little research first, to find out if the subject you're tweeting already has an established hashtag. Also, check Suggestions and Tips and Example Uses below for ettiquette and general usage.

Finally, track other tweets on the subjects you're interested in (ie: those containing the appropriate hashtags) by browsing/searching at Hashtags.org, TwitterGroups, TweetChat, TweetGrid, Twitterfall, etc. You can set it up with RSS feeds as well.

 

Use of hashtags 

Hashtags were popularized during the San Diego forest fires in 2007 when Nate Ritter used the hashtag "#sandiegofire" to identify his updates related to the disaster. 



 

Chris Messina wrote up this use in his post on Twitter hashtags for emergency coordination and disaster relief. 

Subsequent uses have emerged, especially alongside Twitter's track feature and the development of hashtags.org, which shows useful graphs of popularity and recency of hashtags. Another useful tool was the Terraminds twitter search engine that allowed for searching for arbitrary hashtags (search for #hashtag), but is now shut down.

 

Suggestions and tips 

The use of hashtags is still an emergent phenomena, and as such, etiquette is negotiable, though some have already expressed their distaste for hashtags. 

Used sparingly and respectfully, hashtags can provide useful context and cues for recall, as well as increased utility for the track feature. Used excessively can cause annoyance, confusion or frustration, and may lead people to stop following you. It's best to use hashtags explicitly when they're going to add value, rather than on every word in an update. 

A good rule of thumb to follow is to focus on your update first, and only if it quantitatively adds value, to append one-three hashtags. There are no hard and fast rules, but Twitter should continue to be about answering the simple question: "What are you doing" rather than "What tags apply to what you're doing?"

 

CamelCase

When creating a hashtag for something that may consist of two or more words its a good idea to use the "CamelCase" format to maintain legibility. The idea is to join words with each words initial letter capitalized. For example if I wanted to create a hashtag  for south Africa, I would type out: #SouthAfrica instead of #southafrica

 

Example uses 

Events or conferences, e.g.: "Tara's presentation on communities was great! #barcampblock" 
Disasters: "#sandiegofire A shelter has opened up downtown for fire refugees." 
Memes: "My #themeword for 2008 is conduct." 
Context: "I can't believe anyone would design software like this! #microsoftoffice" 
Recall: "Buy some toilet paper. #todo"
Quote: "Great minds discuss ideas. Average minds discuss events. Small minds discuss people." ~Eleanor Roosevelt #quote
 

Further reading  

(In rough chronological order) 

Twitter Hashtags: Nonprofits Speak Up by Devon Smith
An Introduction to Twitter Hashtags on Wild Apricot Blog
Carfi and Barnett on Support Tag Beacons by Stowe Boyd (Seminal post from 2006 on what would eventually be referred to as hashtags)
Groups for Twitter or a Proposal for Twitter Tag Channels Felgi by Chris Messina (Discussing the use of the hash # character)
Channels Will Improve the Twitter Experience by Brian Solis 
A question for Twitter users out there by Steven Hodson 
Twitter Hashtags: A Quickie by Stephanie Booth 
Twitter #Hashtags Backlash Begins by Stowe Boyd 
Twitter, TwitBox and hashtags by Steven Hodson 
Twitter Supports 'Tracking' But Not #Hashtags? by Stowe Boyd 
Tracking vs. Hashtags by Colby Palmer 
Twitter hashtags for emergency coordination and disaster relief by Chris Messina 
California Fire Followers Set Twitter Ablaze by Michael Calore, Wired 
Speaking at San Diego BarCamp 2007 by Nate Ritter (account of tweeting #sandiegofire information)
What does # mean in a twitter pos

[Zoro3012]

They are used to create trending topics (on the right hand side of your timeline) they basically show the most popular things people are talking about

[Bob Smith]

ur hot like ur self cause i like u