What is a bitcoin SPV & how does it work?
Could you elaborate on the concept of a Bitcoin Simplified Payment Verification (SPV) and its operational mechanism? I'm curious to understand how it enables users to verify transactions without downloading the entire blockchain. Specifically, how does SPV work to ensure the security and integrity of transactions, while maintaining a relatively lightweight verification process? Additionally, what are the key benefits and limitations of using SPV in comparison to traditional full node verification?