Great question, mate!

Bitcoin nodes are computers that maintain a copy of the entire Bitcoin blockchain and enforce the consensus rules of the system. They validate transactions and blocks on the network.

Lightning Network nodes, on the other hand, operate on a layer above the Bitcoin blockchain. They don't need to store or validate the entire blockchain. Instead, they manage channels for making off-chain transactions which are secure and instant with lower fees.

So essentially, Bitcoin nodes handle all transactions across network while Lightning Network nodes deal with off-chain transactions between specific parties!