Transactions aren’t written to the ledger individually; they are grouped into Blocks approximately every 10 minutes.
Each block contains a Header that includes the hash of the previous block.
⛓️ Why it’s called a Blockchain
Because each block references the previous block’s hash, altering a single past transaction breaks the hash chain for all subsequent blocks. To tamper with history, an attacker would have to re-do all the Proof of Work for that block and all blocks after it!
🧠 Today's Key Takeaway
- Blocks group transactions together with timestamps and cryptographic links.
- The chain of hashes makes history immutable and tamper-resistant.
