The block time for Ethereum is set to between 14 and 15 seconds, while for bitcoin it is on average 10 minutes. Blocks hold batches of valid transactions that are hashed and encoded into a Merkle tree. Each block includes the cryptographic hash of the prior block in the blockchain, linking the two. This iterative process confirms the integrity of the previous block, all the way back to the initial block, which is known as the genesis block.
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