A full node is a fully-validating node that follows the rules of the blockchain, votes for new BIPs, validates transactions, and maintains a complete record of the Bitcoin blockchain. Full nodes are crucial for the security and decentralization of the blockchain. Full nodes are non-custodial, but not all non-custodial wallets are full nodes.
Lightweight nodes are nodes that let Bitcoin users easily enter and exit the network to create and accept payments. These nodes aren’t responsible for maintaining the integrity of the blockchain and are simply there to help less-technical users access bitcoin payments. Custodial mobile wallets fall under this type of node.
Lightning Network nodes create, maintain, and fund bidirectional payment channels that help the network exist.
- They route payments through the network through onion routing.
- They maintain channel liquidity so that they are prepared to bounce transactions through the network.
- Some nodes may choose to operate as watchtowers.