This (#) is a hashtag. It is used to identify key words, topics, locations or kitschy slogans within a tweet. Hastags can occur anywhere within your tweet – beginning, middle, or end. While some people pepper their tweets with hashtags with the hopes of appearing in more search results, it is recommended to use a maximum of two. Hashtag spammers, need not apply.
Clicking on a hashtag within a tweet will show you all the other tweets in that category – the same as if you were to use Twitter Search, which is found at the top of your computer screen.
It is important to highlight that a hashtag can be creative and unique! For example, in Kingston, Ontario, Canada the most popular hashtag is #ygk. Ygk? What does that mean? If you’ve ever used the Kingston Airport you would know – as it is the local airport code. The reason behind the popularity of this hashtag is that there is a Kingston, Nova Scotia, Kingston, Jamaica, and a few recording artists with a similar name. If you search “Kingston” you may not get the right one. As a result, local Tweeters began hashtagging #ygk as a means to identify their location.
Hopefully this enlightens the world of hashtags.