The definition of a node can vary greatly depending on the context used. When it comes to computer or telecommunications networks, nodes can offer different purposes, acting as either a redistribution point or a communication end point. Typically a node consists of a physical network device, but there are certain cases where virtual nodes are used.
Simply put, a network node is a point at which messages can be created, received, or transmitted. Here we will discuss the different types of Bitcoin nodes: Full Nodes, Super Nodes, Miner Nodes, and SPV Client.
Bitcoin Nodes
Diving in the context of blockchains, which is designed as a distributed system of a network of computer nodes, is what allows Bitcoin to be used as a decentralized peer-to-peer (P2P) digital currency that is censorship-resistant by design, without the need for intermediaries during user-to-user exchanges ( no matter how far away it is).
Blockchain nodes are therefore responsible for acting as a point of communication that can perform different functions. Any computer or device that connects to the Bitcoin interface can be considered a node, in the sense that they communicate with each other in some way. These nodes can also transmit transaction and block information across a distributed network of computers using Bitcoin's peer-to-peer (P2P) network protocol. However, each computing node is defined according to its specific functions, which is why there are different types of Bitcoin nodes.
Full Knot
Full nodes are the ones that actually support and secure Bitcoin, and they are indispensable to the network. These nodes are also called full validating nodes because they participate in the process of validating transactions and blocks, contrary to the consensus rules of the system. Full nodes can also relay new transactions and blocks on the blockchain
Typically, a full node downloads a copy of the Bitcoin blockchain, with every block and transaction, but this is not a requirement for a full node (a shortened copy of the blockchain can be used instead).
A Bitcoin full node can be installed using various software implementations, but the most commonly used and popular is Bitcoin Core. These are the minimum requirements to run a full Bitcoin Core node:
A laptop or laptop running the latest version of Windows, Mac OS X or Linux.
200 GB of free disk space.
2GB of random access memory (RAM).n
High-speed Internet connection with a transfer speed of at least 50 kB/s.
Unlimited connection or connection with a large download limit. Full nodes can download 200 GB per month or more and download usage is 20 GB per month. You will also need to download ~200GB the first time you run your full node.
Your full node should be running at least 6 hours a day. Even better if it works around the clock (24/7)
Many voluntary organizations and users work with Bitcoin core nodes to help the Bitcoin ecosystem. There are currently around 9,700 public nodes running on the Bitcoin network. Note that this number only includes public nodes, which refer to Bitcoin tracking nodes that are visible and accessible (aka. Listening nodes).
Apart from public nodes, there are many other hidden nodes that are not visible (untracked nodes). These nodes typically operate within the Firewall through hidden protocols such as Tor or simply because they are configured to not monitor the connection.
Tracking Nodes (Super Nodes)
Essentially, a tracking node or supernode is the same as a full node that is publicly accessible. It communicates and provides information to any other node that decides to connect to it. Therefore, a supernode is basically a redistribution point that can act as both a data source and a communication bridge.
A trusted supernode typically operates 24/7 and has multiple established connections relaying blockchain history and transaction data to multiple nodes around the world. For this reason, a supernode will likely require more computing power and a better internet connection compared to a full hidden node.
Node Miners
To be able to mine Bitcoin competitively, at the moment, you need to be provided with specialized hardware devices and programs. These programs (software) are not directly connected to Bitcoin Core, but run in parallel in an attempt to mine Bitcoin blocks. The miner can choose to work independently (solo miner) or in a group (pool miner)
While solo full node miners use their own copy of the blockchain, pool miners work together, each contributing their own hash power. In a mining pool, only a pool administrator is required to run a full node, which can be called a pool full node miner.
Lightweight или SPV Clients
Also known as Simplified Payment Verification (SPV), lightweight clients are those clients that use the Bitcoin network but do not actually act as a full node. Thus, SPV clients do not contribute to the security of the network because they do not store a copy of the blockchain and do not participate in the process of verifying and confirming transactions.
In short, SPV is a method through which a user can check whether any transactions were included in a block or not, without having to download the data of the entire block. Thus, SPV clients rely on information provided by other full nodes (super nodes). Lightweight clients work as communication endpoints and are used by many cryptocurrency wallets.
Client vs Mining Node
It is important to note that running a full node is not the same as running a full mining node. While miners have to invest in expensive mining hardware and software, anyone can run a full validating node. Moreover, before attempting to mine a block, the miner must collect pending transactions that were previously accepted as valid by full nodes. The miner then creates a candidate block (with a group of transactions) and tries to mine that block. If the miner is able to find the correct solution for this block, he will broadcast it to the network, and the remaining full nodes will check the validity of this block. Therefore, consensus rules are determined and protected by a distributed network of validating nodes rather than by miners.
Conclusion
Bitcoin nodes communicate with each other through the Bitcoin P2P network protocol, and by doing so they guarantee the integrity of the system. A node that misuses or tries to spread incorrect information is quickly recognized by honest nodes and disconnected from the network.
While there are no financial rewards to running a full validating node, it is highly recommended as it provides trust, security, and privacy to users. Full nodes enforce the rules. They protect the blockchain from attacks and fraud (such as double spending). Additionally, a full node does not have to trust others and it allows the user to have complete control over their money.
