A "Unicorn Startup" refers to a privately held startup company valued at over $1 billion. The term was coined by venture capitalist Aileen Lee in 2013 to highlight the rarity of such successful companies. These startups often attract significant investment from venture capitalists and are typically in the technology sector. Unicorns are known for their rapid growth and innovative business models. Examples of well-known unicorns include Uber, Airbnb, and SpaceX. The valuation of these companies is often based on their potential for future growth rather than current profits, making them a focal point in the startup ecosystem.