This is What Trended This Year:
Do you remember that unavoidable song from last year?
It was "Hello," by British singer Adele.
People loved Adele and her song.
So when she appeared on comedian James Corden's late-night television show, lots of people watched. And many who did not watch the show that night watched her appearance later on YouTube.
Their viewing made Adele's turn on Corden's popular "Carpool Karaoke" segment the most popular YouTube video of 2016. The video of Adele riding in the car with Corden and singing her hit songs was played almost 140 million times in 2016.
The most popular Twitter topics of the year were: the Olympic Games in Rio de Janeiro, the U.S. Election, PokemonGo, the Euro 2016 soccer tournament, the Oscars and Brexit.
If you would like to look back at the Olympics and the European soccer tournament, please visit our story about the 2016 year in sports.
U.S. election
In the U.S., Donald Trump won the election for president on November 8. The months before and after the election were filled with online commentary about the candidates.
Early in the year, the election news revolved around the Republican and Democratic Party primaries. Republican candidates — including Trump, Marco Rubio, Ted Cruz, Ben Carson, John Kasich and Jeb Bush – were trying to rally voters around the country. Trump won enough votes and delegates to be named as his party's candidate at the Republican National Convention in Cleveland, Ohio in July.
Hillary Clinton won the Democratic Party's nomination at the convention in Philadelphia after a competitive series of primaries with Vermont senator Bernie Sanders.
Clinton's and Trump's primary victories set up a heated contest from late summer through Election Day. No tweet summed up the rivalry more than Clinton's "delete your account" tweet to Trump.
Clinton's tweet came after Trump wrote: "Obama just endorsed Crooked Hillary. He wants four more years of Obama — but nobody else does!"
The tweet came out on June 9 and was liked and retweeted over 1.2 million times.
Another important question arose during the debates between Clinton and Trump. It was: "Are you a nasty woman or a bad hombre?" The question had social media users casting their votes and explaining why they considered themselves "nasty women" or "bad hombres."
Pokemon Go
People around the world will remember the summer of 2016 for the PokemonGo craze. The peak came in July, when people looking for Pokemon characters gathered on the beach near Los Angeles, California; in front of monuments in Washington, D.C.; and in a city square in Taiwan.
Even an Olympic athlete made news when he spent a lot of money looking for Pokemon characters in Brazil.
The craze took some strange and unfortunate turns. Social media reported on people being robbed, finding dead bodies, causing car accidents and suffering injuries while they searched for Pikachu, Charizard and other characters.
But good things came out of the craze, too: some people said they lost weight because the hunt made them leave the house and walk many kilometers.
The game is less popular now than it was then, but it is still being updated and is now available in over 120 countries.
Disasters and conflicts around the world took their places on trending lists, too. Many people were sad to see the damage suffered by historic Italian cities Amatrice and Accumoli after an earthquake on August 24. The earthquake killed 300 people.
Big hurricanes struck countries in and around the Caribbean Sea. In October, Hurricane Matthew killed 500 people in Haiti and caused damage in southeastern U.S. states.
A disaster that prompted a large amount of concern came from Syria. The country is in the middle of a civil war. It has been going on for about five years. Hundreds of thousands of people have died.
Much of the recent focus is around the city of Aleppo, the second-largest city in Syria.
One of the saddest images of the year caught the attention of many social media users. The video of a small Syrian boy covered in dust and blood sitting in the back of an ambulance made many people understand how difficult life is for people in Aleppo. The video came from the Aleppo Media Center. It has over 4 million views.
Britain exits EU
Many people did not believe it would happen, but British citizens voted on June 23 to leave the European Union. More than 30 million people voted; 52 percent chose to exit. Scotland and Northern Ireland voted to stay in the EU.
British Prime Minister David Cameron, who supported the "stay" campaign, resigned after the vote was counted. Theresa May took his place.
May said "Brexit means Brexit," and in March she will start the legal process to leave the EU. The process may take as long as two years.
After the vote, some "leave" voters said they wished they could change their votes. They were surprised their side won.
And those were the top five viral moments in 2016.