Ten years ago, categorising tweets from a sea of posts became easy when ex-engineer of Google, Chris Messina, used the hash symbol to tag a tweet, thus giving birth to hashtag.

Since then, hashtag has been used to follow world events, mark occasions and start a stream of discussion on a specific subject.

According to Twitter, 125 million hashtags are tweeted every day on average.

According to Business Insider, Hashtag use has grown considerably. In 2007, the most tweeted hashtag was used about 9,000 times. This year, the most popular hashtag has been used over 300 million times.

Some of the most popular hashtags have ushered in an entire lexicon of phrases. #ThrowbackThursday has been tweeted 120 million times, and people have showed off a #ootds, or outfit of the day, over 2 million times.

In celebration of its birthday, Twitter created a 24-hour custom emoji. To check it out, just tweet #Hashtag10.