Twitter, a kind of real time pulse tracking the events as they happen where people from around the gather in moments of triumph, activism, support and fascination to express their views, have revealed the most popular tweets of 2015. The hashtag # JeSuisParis, used to show solidarity with the French capital in the wake of its second terrorist attack, marked the most talked-about moment of the year.

Mirror says that the horrific terrorist attacks in Paris to legalization of same sex marriage in the USA and Ireland, some of the year's most profound events played out on the social media platform.

With around 320 million users worldwide, Twitter reveals some of the most influential and memorable moments of 2015:

#JeSuisParis

The horrific attacks in Paris unfolded in November, the world united to support people in the City of Light using the hashtag #PrayForParis.

Just 10 months prior, terrorists attacked the Paris offices of satirical magazine Charlie Hebdo. After that incident, citizens rallied around the phrase "Je Suis Charlie"to show their support and sorrow for the victims.

#BlackLivesMatter

BlackLivesMatter began as a Twitter hashtag and has come to represent a social movement. The hashtag or phrase was Tweeted 9 million times in 2015.

#MarriageEquality

Same-sex marriage was legalised in the US and Ireland in 2015, with hashtags and phrases associated with that legislation coming third on Twitter's most-tweeted list.

#RefugeesWelcome

As many thousands of refugees from the Middle East and Africa seek asylum in Europe, human rights activists and other citizens around the world have chimed with this hashtag.

#IStandWithAhmed

When 14-year-old Ahmed Mohammed was detained and handcuffed at his Texas school for bringing in his homemade digital clock (the ostensible fear: it was a bomb), a photo of the high school freshman in handcuffs went viral on Twitter.

#National elections

Twitter is a place for voters to partake in public discourse, and this year, conversations around major national elections rocked Twitter as citizens converged on voting booths and ballot boxes in Argentina, Canada, Singapore, India and the UK.

#FIFAWWC

Football fans created a massive global conversation around this summer's FIFA Women's World Cup in Canada.

#PlutoFlyby

Buzz around the spacecraft, which came within 7750 miles of Pluto's surface, and the close-up images it captured, generated more than 1 million Tweets on July 14.

According to Mashable, the most exciting things on twitter in 2015 was getting to watch certain people enter the social media platforms for the first time.

NSA whistleblower Edward Snowden, still a fugitive from U.S. authorities and living in asylum in Russia, finally decided that this was the year he needed to join Twitter

"Can you hear me now?

- Edward Snowden (@Snowden) September 29, 2015"

Another tech luminary, Amazon CEO and founder Jeff Bezos, also finally went live on Twitter to announce the latest advance in his space ambitions via Blue Origin.

"The rarest of beasts - a used rocket. Controlled landing not easy, but done right, can look easy. Check out video: https://t.co/9OypFoxZk3

- Jeff Bezos (@JeffBezos) November 24, 2015"

Twitter also witnessed a special moment when former Olympic athlete Bruce Jenner reintroduced himself to the world as Caitlyn Jenner through her new @Caitlyn_Jenner Twitter account.

"pic.twitter.com/X7FvYrEH2D

- Caitlyn Jenner (@Caitlyn_Jenner) June 1, 2015"

The year 2015 has been another phenomenal year for the Twitter and the social media platform has continued to surprise with its ability to serve as the public bulletin board of the 21st century.