By moving a large part of the transaction off chain to attend to it before adding it back, cost is reduce and it will be faster. That is exactly what the layer two does, thus, freeing space to enable the layer 1 work faster. Yes, the Layer 2 is an additional layer that was built to complement layer 1. You have made a wonderful analogy that explains the Layer 2 very well. Your entry is easy to understand. I wish you success