According to the Cambridge Dictionary, fake news is defined as “false stories that appear to be news, spread on the internet or using other media, usually created to influence political views or as a joke.”
It's important to remember that the media may be biased when presenting news. Above is a helpful chart that demonstrates how different news sources may be biased, and how wide ranging the spectrum of bias can be.
Disclaimer: This is to give an idea of how different news sources may be biased, and not to be taken as an exact indicator of where specific news sources fall.
Click this link for a detailed explanation of the chart and to a new interactive chart.