Accuracy and facts determine if news is "fake" or not. The only real media bias is the bias toward ad revenue. Both the Daily Caller and Huffpost having screaming headlines with the main premise of "Look what the other side is doing to our country." This is click-bate to drive ad revenue. The bias is in the reader. 

Cable news broadcasts whatever sells the most pharmaceuticals and automobiles. Rupert Murdock made a killing recognizing that confirmation bias gets ratings, others have tried to emulate that or vacillate between the two by presenting "both sides" even if the facts only favor one. (CNN I'm looking at you.) Of course actual journalism affects revenue share so they have outsourced that long ago. 

It is easy to detect bias because it exists to sell to a demographic. The challenge is finding the facts and accuracy, and this requires using multiple sources and not allowing your own biases to dictate your sources.