What is a cryptocurrency node: structure and classification of blockchain nodes

A node is one of the key components of a blockchain network, performing the function of distributing and transmitting data among participants. Each such node either processes information in an intermediary manner or serves as an endpoint for receiving it, thereby ensuring the preservation of the network’s decentralization effect. Essentially, a node is a point in the network that receives, verifies, and transmits information between other nodes.

How a Cryptocurrency Node is Structured and How It Works

The technical foundation of a node consists of a computer or server with specialized software and an installed cryptocurrency wallet. Many such nodes, synchronized with each other, create a unified distributed network, which is referred to as the blockchain. This architecture allows for the rapid distribution of massive data streams without a single control center.

The operability of a node directly depends on the computational power of the server and the quality of the internet connection. Almost any device capable of transmitting information over the network is suitable for its launch—from a desktop computer to a specialized server. However, a mandatory requirement is the presence of appropriate software and a constant internet connection. An offline device cannot function as a node, but when connected to the network, it becomes a full-fledged node in the network.

In most blockchains, a node performs three main functions: storing and disseminating data about transactions and wallet balances; ensuring compliance with consensus rules (PoS, PoW algorithms, and their modifications); supporting a distributed ledger containing the complete history of all operations since the network’s inception.

The Role of Nodes in Maintaining Blockchain Stability

To ensure the continuous and reliable operation of a blockchain, a branched network of servers is required that constantly exchanges data. The key value of such an architecture lies in simultaneously achieving two goals: preserving the effect of decentralization and maintaining a high speed of information flow processing.

Thanks to the distribution of nodes across different countries and regions, the blockchain is resilient to local disruptions. Even if the internet goes down in a specific region, the network will continue to function smoothly. However, if control over the majority of nodes becomes concentrated in the hands of one group, this may lead to centralization and limit the advantages of a distributed system.

To prevent such centralization, blockchain networks utilize numerous simple nodes that do not participate in mining but store the complete history of the blockchain. This architectural solution prevents a narrow group of individuals from establishing control over the network. Users who provide computational power to maintain the functionality of the network receive rewards, which serves as an economic incentive to expand the number of active nodes.

Full Nodes as the Foundation of a Decentralized Network

The full node was the first type of node originally designed for the Bitcoin network. Such a node stores all information about blocks and transactions from the launch of the network to the present moment, forming the main framework of the blockchain.

When one participant sends funds, all full nodes immediately register this operation and add it to their local copy of the blockchain. Tens of thousands of full nodes operate simultaneously in one network, constantly synchronizing information. Processing such volumes of data requires significant computational power.

The initial setup of a full node requires complete synchronization—downloading the entire blockchain from scratch. For some networks, this requires a substantial amount of storage. For example, the size of the Bitcoin blockchain at the beginning of 2022 was about 438 Gigabytes, and synchronization could take several weeks. If the connection is interrupted, the node must re-download all data accumulated during its absence.

One of the most significant functions of a full node is the verification of digital signatures for the validation of transactions and blocks. When errors are detected, the node can reject the operation: incorrect formatting, algorithmic failures, duplicate entries, or attempts at manipulation. Owners of full nodes can independently verify incoming transfers and, if desired, participate in the mining process, receiving rewards for validation.

Light Nodes: A Compact Alternative

A light node operates fundamentally differently—it does not store complete information about the blockchain, containing only data about the block to which it is connected. Typically, such a node does not run constantly; it is software that connects to a full node to relay information to the user’s device: account balance details, incoming and outgoing operations.

Essentially, a light node uses a full node as an intermediary for accessing the blockchain. This architecture provides the necessary functionality for using cryptocurrency without the demands for powerful computational resources or large memory capacity. As a result, a light node can even be launched on a mobile phone. Synchronization usually takes just a few seconds.

Pruned Full Nodes: Optimized Storage

A pruned full node downloads the entire blockchain during its initial launch and subsequently automatically loads new blocks while simultaneously deleting old data when a set memory limit is reached. The user can independently determine the maximum size of the node—say, 10 Gigabytes—depending on available storage.

Mining Nodes and the Cryptocurrency Extraction Process

A mining node actively participates in the cryptocurrency extraction process and is used exclusively in blockchains that employ the Proof of Work algorithm. It can be either a full or a light node, but it always requires powerful specialized equipment: a central processing unit (CPU), a graphics processing unit (GPU), or an application-specific integrated circuit (ASIC). Furthermore, it is necessary to install specialized software.

When mining, for example, Bitcoin, the miner solves complex cryptographic tasks. The result of these calculations is the search for a unique value—a hash—that serves as proof of the completed work. The miner then broadcasts the found hash to other nodes for verification against the set parameters. Upon successful validation, the node can add a new block to the chain and receive a reward.

Staking Nodes: An Alternative to Computational Power

A staking node is the counterpart of a mining node but is used in blockchains with the Proof of Stake algorithm. Such a node is necessary for verifying transactions and adding new blocks and can also be either full or light. The key difference is that the reward is not earned for mathematical computations but for holding a certain amount of tokens in the account. Consequently, launching a staking node does not require the purchase of expensive equipment—just the correct configuration of the software and balance top-up.

Masternodes: Enhanced Capabilities and Anonymity

A masternode is a type of full node that stores all information from the blockchain and synchronizes with the network but possesses additional functions. Their main purpose is to ensure anonymity by fragmenting transactions and relaying them through multiple wallets.

The owner of a full node can deploy a masternode upon meeting certain conditions set by the blockchain. Typically, the main requirement is to deposit and hold a specific number of coins in the account. Special server configurations, which vary for each cryptocurrency, must also be implemented.

When an anonymous transaction is executed, the user’s funds are “mixed” through masternodes located around the world and selected at random. The number of mixing rounds varies and can be set manually or automatically. As a result, it becomes virtually impossible to trace the connection between the sender and the recipient.

Masternodes operate on the basis of Proof of Stake algorithms or hybrid PoW/PoS consensus. To incentivize users to create and manage masternodes, the system allocates them a portion of the fees from miners, the amount of which varies depending on the project. A special type of masternode in the NEM network is called a supernode.

Lightning Nodes: Ultra-Fast Payment Channels

The Lightning Network (LN) is a second-layer extension over the Bitcoin blockchain, functioning as a system of user payment channels. In this infrastructure, specialized high-speed nodes synchronize both with each other and the main chain.

The distinctive feature of a Lightning node is that it verifies only transactions directly related to it, in contrast to standard nodes that check all operations in the blockchain. This approach allows for achieving the maximum speed of payment processing.

Validators and Oracles: Auxiliary Node Functions

In decentralized networks, nodes may perform additional specialized roles. A validator node checks and approves transactions, operating according to algorithms specific to each blockchain. An oracle is a node that performs the function of transmitting data from external systems to the blockchain, such as current currency quotes for exchange services.

The oracle script transforms information into a format understandable by smart contracts. The validator subsequently verifies the data received from the oracle alongside all other information in the chain. In this process, one oracle is verified by numerous validators, enhancing the overall security of the system.

Forks: Function Updates and Network Branching

Cryptocurrency projects periodically undergo updates. For changes to take effect across the entire network, they must be accepted by all nodes. Sometimes disagreements arise in the developer and validator community regarding the implementation of certain updates, where one part of the nodes accepts them while the other rejects them. This process is called a fork.

A soft fork represents minor improvements that do not contradict the basic parameters of the blockchain. To implement them, the node owner only needs to update the software. Even if the update is accepted by only a portion of the nodes, the network will continue to function stably.

A hard fork implies significant transformations to the blockchain’s architecture, resulting in a radical change in the types of network nodes. An illustration of this is the event in September 2022 when the cryptocurrency Ethereum transitioned from the Proof of Work algorithm to Proof of Stake (an event known as “The Merge”). As a result, mining nodes were replaced with staking nodes with validator functions.

When disagreements arise over accepting a hard fork, the network splits into two incompatible blockchains. One retains the original parameters, while the other operates according to new rules. Thus, critical updates create a point of divergence where the community chooses which version to support.