Alright, buckle up!

Bitcoin nodes and Lightning nodes are different. A Bitcoin node keeps a full copy of the blockchain and checks all transactions against it. A Lightning node, meanwhile, participates in the Lightning Network by keeping track of off-chain transactions.

Having a Bitcoin or Lightning wallet doesn't automatically make you a node operator. Running a node requires more resources (like disk space for Bitcoin nodes) than just using a wallet.

A node address is like its location on the network - it's how other nodes connect to it. It's different from your Bitcoin or Lightning address, which is where people send funds.

As for public keys, yes! Both Bitcoin and Lighting use public key cryptography. In both systems you've got your private key (which you keep secret) and your public key (which others use to send you money). But remember - in the case of lightning network these keys are used within payment channels not directly posted on-chain as regular bitcoin txs.