A casino online is a website or mobile app that allows players to gamble for real money. These sites are regulated by gambling commissions, which set rules around player protection, game fairness and self-exclusion policies. Some of these websites also offer an identity verification service to prevent underage gambling.

Most online casinos offer signup bonuses to attract new players. These typically come in the form of deposit match offers that can add thousands of dollars in wagering credits to your account. However, they are also often subject to wagering requirements, meaning that you have to play a certain amount of games before you can withdraw the bonus funds.

In addition to signup bonuses, most online casinos offer other promotions to retain existing players. These can include reload bonuses, Game of the Week promos, tournaments and cash prizes for referring friends to the site. In addition, you can normally earn loyalty program points whenever you play at an online casino. These can be redeemed for additional wagering credits and are also often used to enter leaderboard challenges or freeroll tournaments.

In terms of the number of games on offer, most online casinos offer more than 350 titles in their libraries. This includes a huge selection of slots, table games and live dealer tables from a variety of top suppliers. Several online casinos have built their games in-house, but the majority of them are powered by software from third-party developers. These include the market-leading providers like Evolution Gaming, NetEnt and Red Tiger.