Seemingly ordinary events that end up having significant implications due to unexpected outcomes.
The idea of Black Swan events traces back to the rarity of a black swan. The concept of this event consequently follows real-life incidents that appear to happen randomly and have an expected course, only to turn out to be completely different and eventually culminate into noteworthy events of shocking implications.
There have been multiple contextualizations of Black Swan events since ancient times. One of the most popular is that of the statistician Nassim Nicholas Taleb who developed a theory from it called the Black Swan theory. This theory attempts to explain the improbability of an event that has unforeseen implications but logical explanations.
A good example of a Black Swan event is the COVID-19 outbreak, or the Global Financial Crisis of 2008.