What is a node?

A node (from Latin nodus — knot) is any computer connected to a blockchain network. Nodes in a decentralised network communicate via P2P protocols to exchange information about blocks and transactions. Depending on type, a node stores some or all blockchain data.

Disclaimer: this section covers situations specific to the Bitcoin network.

A full node is any computer connected to the blockchain network around the clock and fully synchronised with it. Full nodes store all blockchain data, starting with the genesis block.

Full nodes serve the network free of charge, download and validate every block and its transactions guided solely by the consensus algorithm, and operate independently. Full nodes reject blocks or individual transactions that contradict consensus.

A Bitcoin full node can be launched locally on a physical computer or on a virtual server. To start, download the Bitcoin Core client from bitcoin.org and download the entire chain of blocks. An open TCP port 8333 is required. If you use a software firewall, grant access to avoid the port being blocked.

Owners of full nodes vote on introducing new changes to the Bitcoin network. An increase in such nodes supports decentralisation and makes it harder to adopt protocols solely in the interests of certain groups of players.

A light node is any computer with specialised software connected to a blockchain network. Light nodes do not store all blockchain data, only block headers to confirm the authenticity of the transactions they contain. Light nodes depend on full nodes and can be misled into confirming transactions that contradict the consensus algorithm.

Yes. Bitnodes shows where Bitcoin full nodes are currently active across the globe. The service can also be used to check correct port forwarding.

A masternode is a specially configured full node that shares rewards for maintaining the network with miners. Dash is the best-known example of masternode use.

Masternodes provide increased anonymity, because transaction information is not publicly available on the blockchain but recorded only on masternodes. To launch a masternode, a fixed deposit of the network’s coins is required.

A supernode is a masternode in the NEM network.

A supernode is a walletless endpoint of a cryptocurrency API; public block explorers fall into this category (per Ambisafe’s classification).

NEM; Dash; Syscoin; PIVX and others.

Yes. Running a masternode can be viewed as passive mining, since operators share the proceeds from block generation and validation with miners. Typically, a masternode’s yield is inversely proportional to the coin’s liquidity — high market capitalisation and user activity tend to reduce masternode returns in such a network.

Crypto-coinz.net provides information on daily and annual ROI, the cost to launch a masternode (the deposit that must be frozen), and the number of nodes in the network.

A way of incentivising node operation in the NEM network, based on the Proof-of-Importance (POI) consensus algorithm. The protocol allows a certain number of accounts to “harvest” through a single client. POI considers three factors when determining an account’s importance score (number of coins, the account’s transaction activity, and how long coins remain on the account), which in turn is the probability that the account will find the next block (expressed in prodecimille).

Local harvesting can run only on a local computer, because the NEM client receives the private key, which puts the account’s funds at risk. This form of harvesting is the least popular due to security issues.

This type of harvesting involves creating an intermediary account whose private key is passed to the client. The intermediary account holds no funds, which solves the security problem of local harvesting. Official XEM wallets support only delegated harvesting.

It is the rental of Waves tokens to a mining pool for a reward. The size of the reward depends on the terms of the specific mining pool. A list of leasing pools is presented on the official Waves website.