A welcome bonus is a bonus that a casino offers its players once they join their site. It's a way to appreciate new customers and encourage them to play. However, any winnings from the welcome bonus may have to be used to make other bets before any withdrawals can be made.
The Netherlands is a European country which is well-known for its relaxed and liberal attitudes to many things, including gaming. This means that its citizens are free to enjoy all the fun of online casino games and many of them choose to play on their smartphones using the latest apps from European casinos.