Types of Nodes in Blockchain

In the previous section, you learned about the recordkeeping in the bitcoin blockchain system. You saw how bitcoin uses UTXO’s for transactions and stores the UTXO’s obtained by a node at a given point of time and not the balance of each node. In this section, you will learn about the various types of nodes in the bitcoin blockchain network. Before going into the types of node, let’s take a time instance in the bitcoin blockchain network and analyze how transaction pool works.

In  blockchain at a given point of time, it is not necessary for all the nodes to have the same transactions in their transaction pool. There could be various reasons for this to happen such as network latency, broken connection, less computational power, etc. Bitcoin blockchain also defines the frequency at which blocks should be created inside the network which is set to 10 minutes in the current Bitcoin system.

Now let’s analyze the roles of nodes in the network.

There are three types of nodes in the bitcoin blockchain network:

1. Miner nodes: They create the blocks in the network

2. Full nodes: They store the details of all the blocks in the network

3. SPV nodes: They are nodes that store only the partial details of the blocks in the network

Note: Questions like what are these partial details, what are complete details shall be answered shortly in upcoming videos. So please be patient! We shall address everything.

You will understand these roles better in the upcoming videos. Now, let's see how the blocks are created by the miner in the upcoming video.

The miner node takes the unconfirmed transactions in the mining pool and creates a block. Once a block is created, it gets flooded across the network using the gossip protocol. All the nodes receive the block and first validate the block if the block passes the validation they add it to their respective blockchain otherwise not. To understand the validation of block, let’s first dive into the contents of the block in the next section.