The concept of "fake news" was introduced by the corporate media in order to discredit the independent media. The world is full of information, propaganda and lies readily available in the Internet. People are less prone to take all the corporate media propaganda and lies seriously and are looking for more information. Therefore, the propaganda machine is loosing its grip of the people. They are loosing big time; credibility, readers and profits. Just to add insult to the injury their attempt to discredit the independent media failed and came back with a vengeance. The concept they created now means the biased news pushed by them. Wonderful indeed.

According to Conservapedia:
"Fake news" refers to liberal bias in the media that is so misleading that it is actually false. It can also include assertions of a non-political nature that seem believable but are untrue.

... The motive of fake news is to manipulate public opinion using false reporting and bias. It can be sourced to anonymous government leakers or political operatives. The motive can be as simple as confirmation bias - pandering to an ideological viewership to distribute talking points or maintain ratings."

Link to Conservapedia, worth reading.