From my understanding, a sidechain is just another blockchain with smart contract language capabilities which can speak to the parent chain. And both chains speak to each other using smart contracts for the purpose of knowing what and when to mint and burn assets.
Firstly, what are some current technologies or processes that sidechains are a more efficient alternative to? What are some possible benefits of using a sidechain?
Secondly, what are the steps required to build a sidechain which would work with Cardano? For example if I wanted to build a replica of the EVM sidechain being developed by IOG, what are all the different components I need to build?