## Why Do Blockchain Networks Need (Node)?

In the cryptocurrency world, the term **node** (Node) appears frequently, but many people may still not understand what role nodes play in the blockchain system. This article will explain what a node is, how it works, and why it is essential to the network's operation.

## What Is a Node - An Introductory Understanding

A node is a computer or other device connected to the blockchain network. Its function is to support the network's operation through verifying and relaying various transactions.

The main role of a node is to confirm the validity of all transactions that are grouped into a block. Each node has a unique identifier, which helps distinguish it from other nodes in the network.

For proof-of-work blockchains like Bitcoin or Monero, nodes are fundamental components that revolutionized digital technology, existing since the early days of blockchain technology up to the present.

## How Nodes Work - Key Steps

### Step 1: Distributing and Forwarding Transactions

When a user signs a transaction, the details are sent to a set of nodes. The first node forwards it to other nodes in sequence until the transaction is included in a block or rejected.

### Step 2: Verification in the Mempool

Once the transaction is broadcasted, it enters each node's Mempool. Initially, it is queued for verification. Nodes must verify the transaction's correctness.

If the majority of nodes confirm the transaction is valid, it changes status to ready for processing, meaning it is prepared to be added to the blockchain. Conversely, if deemed invalid, the transaction is canceled.

( Step 3: Adding the Block and Broadcasting to the Network

When the transaction is ready, the miner node )in PoW systems### or the validator (in PoS systems) will add the block to the network.

Once the block is added to the chain, transactions become immutable. Any changes require approval from the majority of nodes, which may include many popular nodes in the blockchain. This creates high security for the system.

( Step 4: Incentives and Correct Mechanisms

Nodes are motivated to follow the system's rules and have safeguards against malicious behavior.

**For Proof-of-Work systems )like Bitcoin###:** Miners must use significant computational power to solve complex cryptographic puzzles. If successful, they receive a block reward. The energy cost of mining makes unprofitable attempts unlikely, incentivizing miners to produce valid blocks.

**For Proof-of-Stake systems:** Validator nodes must lock up a large amount of funds as collateral. If they behave honestly, they earn additional rewards. If malicious, their stake (or "stake") is reduced. This mechanism is designed to ensure nodes operate correctly without requiring large energy expenditure.

## Why Are Nodes Important to Blockchain Systems

Nodes are closely related to the security of the blockchain network. To achieve a decentralized system, the only effective model is Peer-to-Peer, managed efficiently through the blockchain network.

Nodes enable the network to verify transactions fairly without any central authority. Moreover, the more participants running nodes, the harder it becomes for malicious actors to control the network.

They confirm that all users and miners are following the rules. These two features make the network more decentralized and secure. Whatever you do on the network, you will always face nodes.

In reality, without blockchain, there would be no storage for blockchain data in the first place, which is why nodes are critically important to blockchain.

## Types of Nodes - Differences and Roles

Nodes come in various types, with the two main types being Full Nodes and Light Nodes. However, there are other important node types that are fundamental to infrastructure.

( Full Node - Full Node

A Full Node stores a complete copy of the digital ledger )ledger### of the network. This type of node forms the backbone of most blockchains.

It maintains the entire history of the chain and communicates with other Full Nodes. Additionally, Full Nodes provide copies of the chain to new nodes joining the network, making them the true backbone. This explains why most blockchains require Full Nodes.

( Miner Nodes - Miner Nodes

Miner nodes are participants responsible for verifying transactions and adding them to the blockchain. In proof-of-work blockchains, mining requires enormous computational power to solve complex mathematical problems.

They are rewarded with digital currency for their work.

) Validator Nodes - Validator Nodes

Validator nodes are similar to miner nodes but operate on proof-of-stake blockchains. They verify transactions and create blocks.

However, these nodes do not need to solve complex calculations; instead, they are selected based on the amount of funds ###stake### locked up as collateral. Like miners, validators are rewarded for creating blocks.

( Light Nodes - Light Nodes

Light Nodes do not store the entire blockchain but only download block headers. They require minimal technical resources, meaning they do not need large storage capacity.

Their sole task is to verify transactions on the blockchain using simplified payment verification )SPV###. Not all blockchains use Light Nodes; they are generally popular in blockchains with limited storage space, such as Bitcoin.

## Relationship Between Nodes, Blockchain, and Miners

At the core of cryptocurrency technology and other platforms in the crypto space is the "blockchain" network.

Within the blockchain network, a key system is the "Smart Contract" (Smart Contract), which is an automated contract that can operate independently without intermediaries or third parties. Smart contracts contain computer code.

Unlike traditional systems that store data in a single location, in cryptocurrency networks, data is stored across all nodes to prevent attacks and data tampering on the blockchain.

Miners (Miners) are groups responsible for verifying transaction validity and solving mathematical puzzles. Once verification is complete, the block joins the blockchain, and they receive rewards in digital currency according to the platform's conditions.

## How to Set Up a Node - Basic Steps

Creating a node on the blockchain can be done in three main steps:

**Step 1: Prepare Suitable Hardware**
Users can set up nodes on their own computers. Ensure the device has sufficient performance for operation.

**Step 2: Download and Install Software**
Download blockchain node software from a trusted source and install it on your device.

**Step 3: Run the Software**
After installation, run the software daily so your node can connect to the network.

**Key Factors:** Hardware and Internet Connection

Users need devices with adequate memory, especially when running a Full Node that stores the entire blockchain.

Blockchain nodes upload large amounts of data, so check your internet plan's upload limits to avoid issues later.

Nodes play a vital role in maintaining blockchain security. For those wishing to support a digital currency project, setting up a node is one of the best options.

## Risks and Warnings of Operating a Node

As node popularity continues to grow, it is crucial to understand security and privacy risks. Details are as follows:

( Malware Attacks

Unsecured nodes are vulnerable to malware. Malicious programs can steal sensitive information, such as private keys, leading to financial loss.

) DDoS Attacks

Distributed Denial of Service ###DDoS### attacks can overload nodes with excessive data transmission, causing network disruptions.

( Sybil Attacks

Sybil attacks occur when an attacker creates multiple fake nodes to try to control the network.

) Reorganization Attacks

This attack can happen if a node runs outdated software, causing it to be left behind on a different chain. This may result in financial loss for the node operator.

## Summary

A ###Node### is critically important to the blockchain network, especially in storing and verifying data. It is also a key driver that makes the world of cryptocurrency more interesting and secure.

However, setting up a node is still a new and specialized activity. Investing in nodes requires thorough research to mitigate risks.