Smart Bitcoin (RBTC) is a native RSK token that is used as a gas for performing transactions in an RSK network. Startup RSK started working under the name Rootstock. Its organizers systematically implemented smart contracts like Ethereum on the basis of the Bitcoin network. Enthusiasts of the industry believe that this will significantly support the world's largest cryptocurrency. Because it will only benefit from the fact that the pioneer platform for the complex self-terminating code on the blockchain now has a competitor. At its core, sidechain RSK is a simpler alternative for the existing way to change the Bitcoin code. An attempt to introduce such a solution has already been done, but was crowned with a failure in the debate on the organization of the Bitcoin network. The implementation of such a solution has its pitfalls. After all, even minimal changes can affect the entire system. And the consequences are unpredictable. This is the same as repairing an aircraft engine right in flight. Therefore, developers are trying to introduce all the innovations in the network using side chains or sidechains. With their help, the main network is connected with the new blockchain, but minimizes the risk of unexpected consequences.