Fake news is news which is published with the intent to deceive the reader. The news may have a catchy headine or a photo to attract the reader's attention and encourage the latter to click on a link which takes the reader to another web site. It is a type of clickbait.
According to a news article published on www.defimedia.info on 19 February, there was a story on a "clone" of a news web site in the United Kingdom about a person elected as Miss Mauritius in which it was reported that the person was arrested in the United Kingdom. In an interview with the local newspaper on 20 March, the person stated that she was in Mauritius on 19 February. It would not have been possible for the person to be in the United Kingdom on that day because of the distance between the two locations.
On 20 March, www.lexpress.mu reported that there was a fake news article from "USA Television" stating the President "has been announced as the best President in the world".
The story from the unknown web site ("USA Television") was shared by an unverified Twitter account on 19 March. Fact checking is about verifying the facts included in, for example, a news article. This entails verifying the source of the information. It is assumed that information can be verified by a visit to a government web site if the information seems related to government. The only information available on the government web site was a "tweet".
On social media it is usually not possible to determine whether a story has been verified before it is shared as the story is available on social media before it is published in a newspaper. In the first example, it would have been possible to verify whether the story was true by waiting for it to be published on a web site which is considered as a reliable source of information. The Twitter account mentioned in the second example did not look like a "fake profile" as it appeared on a government web site. The reader would likely view the information as the truth.