What is a node?

A node is the fundamental foundation of blockchain technology. Thanks to them we can create a huge network of interconnected computers that share information in a secure, fast and decentralized way, and allow us to enjoy all the advantages of the chain of blocks. 

EIn computing, a node is, in general, a physical or virtual connection point where you can create, send and receive all kinds of data and information. Thus, from the point of view of blockchain technology and cryptocurrencies, , the nodes are the computers that are interconnected to the network of a cryptocurrency, running the software that is responsible for the operation. 

These nodes are connected to each other through a peer-to-peer network known as RED peer-to-peer (P2P). Which means that all nodes operate in the same way and are equivalent to each other. In addition, the nodes can communicate with each other to transmit and share data and information through said network. In this way, the nodes of a blockchain network can orchestrate all the information necessary for its operation. 

Origin of distributed and interconnected networks 

Bitcoin It was the first cryptocurrency to employ a network of nodes to operate decentralized and autonomously through the blockchain. However, this was not the first to create or introduce the concept of node from a P2P network. We owe this honor to Napster, developed in 1999 by entrepreneurs Sean Parker y Shawn Fanning In the United States, they were the ones who popularized the concept of a massively distributed network among users. 

Napster was a project created with the purpose of allowing the exchange and distribution of music. All your users need was to download your software and join the network. This was largely accepted, reaching over 26 million users. An incredible amount considering that at that time there were only 248 million Internet users. And, although Napster operated centrally, since it had a central server to keep subscribers online, Napster users could exchange their music files without any intermediaries, allowing direct connections between them. But due to the fact that Napster distributed music without payment of royalties, the platform was eventually shut down. 

Subsequently, the project SETI @ Home He was the second to implement the node structure in the network, in order to conduct research and analyze data from radio telescopes, aimed at searching for life and extraterrestrial intelligence. This project was developed in the same way in 1999, and was directed by the laboratory Space Science Laboratory from the University of California, United States. At SETI @ Home, any user who had a computer with an Internet connection, and who was interested in carrying out this type of work, could connect to the project simply by downloading and running the software, which was also free. Unfortunately the SETI @ Home project has stopped working recently. 

So, the way of operating of this last project is the one that has the greatest similarity and relationship with the current functioning of node networks in Bitcoin blockchains and other cryptocurrencies.

How does a Bitcoin node work?

Anyone wishing to join and contribute to the Bitcoin system network can do so freely by downloading and installing the Bitcoin software. Bitcoin Core on your computer. If you are interested in doing this process, we invite you to see this article where we easily explain how can you install a Bitcoin node on your computer in a very short time. 

But how does the node work? The operation of the Bitcoin peer network begins with the erection of the first node. Satoshi Nakamoto was the first to run a Bitcoin node, followed by Hal Finney. Now, at this point, with a single node, it cannot be called a network. This requires more and more nodes to join. At this point, the computers or computing equipment run the Bitcoin Core software of the Bitcoin system and begin to join.

From that moment they begin to synchronize with each other and begin their operation and functioning process, which continues to be repeated with each new node added to the network, exchanging information so that everyone works in a coordinated way.

In this way, the Bitcoin blockchain operates as a decentralized system. This is why the nodes must share and distribute the responsibility for creating, storing and transmitting the information within the network. There are no levels or hierarchies, in the Bitcoin blockchain all nodes operate equally. 

Once connected, the nodes can perform different functions, such as the retransmission or storage of data or services for sending or receiving operations. As well as a mining service for the creation of new blocks, validation and confirmation of transactions, among others.

Although there are several types of nodes that perform different functions from each other, all interconnected nodes are governed by the same established consensus protocol rules. In fact, each one will reach its own conclusion about the validity of a transaction, regardless of the other nodes. 

Likewise, the nodes in the Bitcoin network and in the network of other cryptocurrencies can be those connection points that relay all the information they receive, or they can be that final communication point that stores all the data. 

Nowadays, for a node to function properly it requires a certain degree of computing power and capacity, in addition to sufficient storage space. For this reason, it is common today for many users to invest in the computing resources they wish to allocate to play the role of nodes.

Types of nodes in the Bitcoin network

As we already mentioned, in Bitcoin there are several types of nodes, and each one of them performs specific and different functions. 

Full nodes 

They are computer equipment or computers that implement the Bitcoin client, being the most common Bitcoin Core, and store an exact, complete and up-to-date copy of the Bitcoin blockchain. The complete nodes are those that enforce all the rules of the Bitcoin protocol, and therefore, are the ones that truly provide robustness, security and stability to the network. 

Full nodes broadcast their own transactions, while they will also broadcast those of other users. In addition, they update the blockchain each time a new block is generated, previously confirming that it complies with the consensus rules established in the system. For example, that the amount of bitcoins generated as a reward is correct, that the block size does not exceed the limit size, that the signatures of the added transactions are valid, that there are no double spending problems, among others.

If any of these or another protocol rule is violated, the full nodes will immediately reject the generated block, guaranteeing the maximum security and integrity of the network.

Supernodes

Supernodes, also known as listening nodes, are full nodes that operate on the Bitcoin network in a public and open way. Currently, it is estimated that there are around 10.000 public nodes known and distributed worldwide. 

These nodes operate as a point of communication and interconnection with other nodes in the network. Any node that wants to connect to a supernode can do so in the open. Since they generally operate continuously and uninterruptedly to transmit data and information to various points in the network.  

Mining nodes

The nodes of mining is., As the name implies, are those complete nodes that, in addition to storing a complete copy of the blockchain, also run mining software cwith the purpose of mining bitcoins and generating new blocks within the blockchain. In addition, the mining nodes are in charge of receiving and transmitting the transactions that are carried out in the network. 

Although in 2009 bitcoins could be mined with a simple CPU, nowadays, and due to the enormous difficulty network, it takes specialized teams to engage in this activity. Although there are also new modalities such as mining pool that allow to unite the computational power of a group of miners, where only the administrator of the mining group will execute the complete node.

Light Nodes

Light nodes, also known as broadcast nodes are those who depend on a third party to perform validations of transactions on the network. These nodes do not require storing a full copy of the blockchain, but instead receive the blockchain information from the supernodes. 

By not downloading a full copy of the blockchain, the lightweight nodes are executable on mobile devices like phones and tablets. And they are used to run the services of wallets and purses to verify whether or not the transactions made are included in the blockchain. 

Security and protection of the Bitcoin network

Full nodes or supernodes that are constantly connected to the Bitcoin network continuously receive, store, and transmit all blockchain updates. Every time a valid block is generated, these nodes update and store the new information.

This operation provides robustness and security to the network against attacks by malicious actors or system failures. Since if a power failure or a hacking attempt occurs in one of the nodes, all the others have a backup of the current information. Something that would be impossible if we were talking about a central server. 

Thus, even if a large part of the node network suffers a failure or hacking, with just one node that is intact, the Bitcoin network can be kept operational. Since this would allow to recover all the blockchain and the information stored in it. So the more number of full nodes there are in the Bitcoin network, the more secure and reliable it will be.

Nodes in other blockchain networks

Other blockchain and cryptocurrencies like Dash o PivX they employ masternodes o master nodes, which in addition to being able to execute the functions of the nodes that we have already mentioned, can also participate in other types of functions and services within a blockchain. Generally, for the execution of this type of nodes, the possession of a certain amount of cryptocurrencies is required to guarantee the correct participation of the node within the blockchain.  

The functions that a masternode they depend on and are linked to the type of blockchain where they will be executed. Thus, they will be able to participate in voting events, execute protocol operations and comply with all the rules established within a blockchain. In addition, they can offer other functions such as validating or transmitting transactions. Likewise, this type of nodes must remain operational continuously and uninterrupted. And, they must also have good processing capacity and storage space. 

There are also data storage nodes like the ones we can see in blockchain as Both. The function of these nodes is to build a giant data cloud-style data storage network. But controlled entirely by the smart contracts of the Sia blockchain. As a result, Sia users can rent storage space on these storage nodes. From there, they can upload the data they want in a secure and completely decentralized way. 

As you can see, the purpose and usefulness of the nodes is varied. And everything depends on the infrastructure and development of the network of which they are part.