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.
Israel is known as the "only democracy in the Middle East", and is a strategic ally of the west. Gambling is strictly regulated and mostly illegal. Technically, online and mobile casinos are also prohibited, but in practice, playing in foreign casinos is possible, and players are not actively prosecuted. This makes mobile online gambling casinos relatively popular.