What is Fake News?
Fake news is usually real news that is taken out of context or manipulated. It could also be entirely made up or just parody. This type of news has always existed (think National Enquirer, or "Yellow Journalism"), but has become more mainstream due to the fast spreading of fake news on social media. The term "fake news" spread rapidly during and after the 2016 U.S. Presidential campaign.
Here are some resources that will help you to evaluate news.