Sidechain

A sidechain is an independent blockchain that runs alongside a main chain and is connected to it by a bridge, so assets can move between the two. Unlike a rollup, a sidechain has its own consensus and validator set and does not inherit the security of the main chain; if its validators collude or fail, the main chain cannot correct it. That independence is also its appeal, because a sidechain can choose its own block times, fees and rules, often making transactions much cheaper. When using one, remember that your bridged balance is only as safe as the sidechain's validator set and the bridge contract holding the original assets.