Bitcoin and Ethereum nodes differ in their structure, functionality, and role within their respective networks.

Bitcoin Nodes
Bitcoin nodes primarily validate and propagate transactions within the Bitcoin blockchain. A full Bitcoin node stores the entire transaction history and enforces consensus rules, such as verifying signatures and ensuring double-spending does not occur. Bitcoin also has light nodes that rely on full nodes for transaction verification. Mining nodes use computational power to solve cryptographic puzzles and add new blocks to the chain through the Proof-of-Work (PoW) mechanism. Bitcoin’s blockchain is relatively simple, focusing solely on transactions and security.

Ethereum Nodes
Ethereum nodes function similarly but have added complexity due to smart contracts. Ethereum’s full nodes store the entire blockchain and execute smart contract code, while light nodes sync only essential data. Ethereum also has validator nodes instead of mining nodes, as Ethereum now operates on a Proof-of-Stake (PoS) consensus mechanism. Validators stake ETH and confirm transactions rather than compete via computational power. Ethereum nodes also interact with the Ethereum Virtual Machine (EVM), processing smart contracts and decentralized applications (dApps).

Overall, Bitcoin nodes focus on transaction verification and security, while Ethereum nodes handle both transactions and smart contract execution, making them more resource-intensive.