I'd like to understand blockchain stuff. Maybe I should start collecting some questions and notes here?

Questions

• What is a blockchain and how does it work?
  • I know this one, but it's worth writing down in my own words
• What does this do that cannot be done with other systems?
• Does what it can do make it worth the cost vs other systems?
• Why would anyone spend money on an NFT?
• How can distributed identity work without permanently disclosing personal info on an immutable chain?
  • Look into Zero-Knowledge Proofs and Yao's Millionaires' problem
  • Also reading:
    • Blockchain Identity Management: The Definitive Guide (2021 Update)
    • Self-Sovereign Identity: The Ultimate Beginners Guide!
• Compare & contrast smart contracts with serverless lambda functions