Explain the concept of 'Unicorn'. Also mention the name of the startup became the India's first Unicorn.

A Unicorn is a privately held start-up company which has achieved a valuation US$ 1 billion. This term was coined by venture capitalist Aileen Lee, first time in 2013. Unicorn, a mythical animal represents the statistical rarity of successful ventures. A start-up is referred as a Unicorn if it has following features: (i) A privately held start-up. (ii) Valuation of start-up reaches US$ 1 Billion. (iii) Emphasis is on the rarity of success of such start-up. (iv) Other common features are new ideas, disruptive innovation, consumer focus, high on technology etc. However, it is important to note that in case the valuation of any start-up slips below US$ 1 billion it can lose its status of 'Unicorn'. Hence a start-up may be Unicorn at one point of time and may not be at another point of time. In September 2011, InMobi, an ad-tech startup, became the first Unicorn of India. SoftBank invested US$ 200 million in InMobi valuing the mobile advertising company at over US$ 1 billion, making it India's first unicorn.