How do Layer 1 protocols like Ethereum and Bitcoin differ from Layer 2 solutions such as the Lightning Network or Optimistic Rollups? What are the unique challenges and advantages of each, and how do they impact scalability, security, and user experience in the blockchain ecosystem?
Here is a list of many Bitcoin L2 projects. According to this website, there are 77 active layer 2 on bitcoin network.
https://btcl2.info/Some bitcoin most know layer 2 solutions:
Lightning network
Liquid network (
https://liquid.network/)