There is a difference in media bias and fake news. Media bias might look like not including the whole picture in a story, or omitting facts that cast an aspect in a negative light and highlighting others. Media bias can cause the spread of misinformation. Fake news is specifically untrue and seeks to spread disinformation.
https://www.ifla.org/publications/node/11174
Source: Adelphi University Fake News and Alternative Facts: A Guide to News Literacy