A free spin is essentially an offer that a casino gives to its players to spin the reels free of charge and have the opportunity to win real cash. The free spins may be given to both new and current customers, and it's one way to reward and encourage them to continue betting.
India is the country that has the world's second largest population. This means that it is a place that online casino operators are very keen to get involved in. The potential size of the market means that there are huge rewards for anyone who is able to set up a popular online casino in India.