The roots of Blackjack are not entirely clear. Some say that a similar version of this game was played in Spain in 1570. Others think that a game like this was played in France about 1600. It is also common that it originated in Italy. Regardless of that, the name still comes from America.
There was a producer of card tables, whose logo was Blackjack, and since then this popular game was named like this. The main goal of the game is to have a hand of cards, which is greater than the one possessed by the dealer but not higher than 21 points. You can play Blackjack with several other players on a table. The one who is closer to the number 21 wins. Nowadays, there are many variants of this game, plenty of them available online.
The rules are always the same, so you can switch between casinos and play the same game. The online casino is also open 24 hours a day and 7 days per week, so you can visit any time and have a game or two. The online version clearly provides more flexibility. It is also very good for practicing and honing the skills. You can always play without the risk of losing money. This gets you more experience while you play. Right there you can always try new strategies or tactics.
Later on you can bring those to a real game and try if it brings any profits. The online casino had a bad image in the past, because of the payment methods not always being very secure. With the arrival of PayPal it is possible to make a safe transaction, without worrying about the outcome. The sensitive data is being fully secured, while the users can spend their time on playing the games.