A blockchain is a system that allows people to exchange value without intermediaries. It has a set of rules that define how transactions are validated, recorded, and updated on a distributed ledger.

The rules of a blockchain are not fixed or imposed by a central authority. They are created and updated by the people who build and use the blockchain. There are two main ways that this can happen:

The code: The developers who create the software that runs the blockchain can write the initial rules and update them as needed. They can also propose changes to the code that require approval from other participants.

The governance: The users who hold tokens that represent value or rights on the blockchain can influence the direction and evolution of the system. They can vote on proposals, suggest improvements, or delegate their power to others.

These two methods can work together or separately depending on the design and purpose of each blockchain. Some blockchains have more centralized or decentralized governance than others.The goal is to create a system that is fair, transparent, secure, and efficient for all stakeholders.