It is also possible to buy “gems”, another type of currency, with your credit card. Magic Arena is a free to play platform, with a card acquisition system similar to other online games, through Boosters that can be purchased with in-game currencies, achieved through daily missions, tournament prizes and the like. The game isn't so “pretty”, but it is very useful to understand some concepts like the stack and trigger resolution. There's a tournament system divided by format, and there's all the eternal formats there, Draft and Sealed events, plus a casual area. It is only available for PC and to purchase an “official account”, there is a fee of 5 dollars.
Magic: the Gathering Online (MTGO) was the first virtual platform created to play Magic, with its own currency system and in-game commerce and buy cards as if they were real. In addition, there is also a difference between the available formats. The main difference between the two is the economy and the ways to acquire new cards.
What is the difference between Magic Arena and MTGO?