A program that completely validates blocks and transactions is known as a full node. Nearly all full nodes also support the network by accepting blocks and transactions from other full nodes, authenticating them, and then forwarding them to further full nodes.
Most full nodes also provide services to lightweight clients, letting them send transactions to the network and alerting them when a transaction impacts their wallets. However, clients won’t be able to connect through the peer-to-peer network; they will have to use centralized services in its place if not enough nodes carry out this function.
Although many individuals and groups give their time to host full nodes using new processing and bandwidth resources, more volunteers are required to support Bitcoin’s expansion.
A full node typically downloads a copy of the Bitcoin blockchain with each block and transaction; however, doing so is not necessary to qualify as a full node (a reduced copy of the blockchain may be used instead).
The pruned full node is one sort of full node that downloads blocks from the chain’s beginning to a specific threshold before deleting the oldest blocks. The complete blockchain is hosted by archival full nodes, which consume much more hard disk space than the trimmed full node.
