Mental model of a Blockchain

This is my mental model of what Blockchain is.

Blockchain is a complex system yet very simple concept to grasp if we have the right mental model of what it does and how it works. I have seen people confusing between what is the difference between Blockchain, Blockchain Network, Blockchain Node and Account on Blockchain. In this post, I want to clarify and hopefully give a glimpse of the mental model of blockchain that I have.

There are few statements I want to make regarding the mental model.

• Blockchain Network is a collection of Blockchain Nodes.
• Blockchain is a property of the Blockchain Network.
• Blockchain Nodes are interfaces to connect to Blockchain.
• Accounts provide us an identity on Blockchain.

Blockchain Network is a collection of Blockchain Nodes.

A Blockchain network is a collection of Blockchain nodes and it does not involve accounts or interfaces to connect to Blockchain. It is just a collection of nodes which have a copy of Blockchain and take part in the network consensus.

Blockchain is a property of the network.

Blockchain is a property of Blockchain network rather than a blockchain node. It is not a property of a specific node because you can modify your copy of Blockchain in anyway eg: You can go to the database where the blockchain is stored and change it, maybe make some transactions disappear, but that does not effect the actual Blockchain. So what you have is a copy of the Blockchain and Blockchain is a property of the network rather than an individual node.

Blockchain Nodes are interfaces to connect to blockchain.

There are two parts to a blockchain node, one is the part that deals with taking part in network consensus which is taken care of by the blockchain code without user intervention. The part that is important to the developer is the interface it provides to talk to the blockchain. This is exactly what light clients do, they give us a way to interact with blockchain without involving in network consensus. So from a developer’s perspective Blockchain Nodes are a medium by which we can connect to blockchain.

Accounts provide us an identity on Blockchain.

Accounts have nothing to do with the blockchain nodes or interfaces we are using to talk to blockchain. Accounts are a standlone entities which provide us identity on a blockchain. The state of the accounts is maintained in the Blockchain.

The following is a picture of how I view the Blockchain in my mind.

Note

This is a mental model of the Blockchain from a logical standpoint. The does not represent the actual stacking of things like accounts and node together for ease of use and security purposes.