Sidechains can be thought of as independent blockchains that have a very specific purpose, function independently of the main chain or other sidechains, and provide for a scalable solution for the decentralized applications of tomorrow. A sidechain is effectively a local road parallel to a highway. Perhaps this local road has several more intersections, stop signs, and traffic moving in different directions. If these intersections and stop signs were put on the highway, things would inevitably slow to a full-blown traffic jam. By appending local roads parallel to the highway, it allows specific traffic to exit and arrive at desired locations at specific times, which keeps the grand highway of the main chain uncongested.