Unicorns
A Unicorn is a startup company that has been valued at over $1 Billion. Obviously there are very few such enterprises, but examples of them are Apple, Google, Uber, Airbnb, and Dropbox.
There has been a great increase in the number of unicorns in recent years, which has led to some people calling this upward trend unsustainable. There were 223 Unicorns as of March 2017.