Blockchain networks are often described as permanent and unchangeable, but that does not mean the software running them stays the same forever. Like any complex technology, blockchains need to evolve. Developers discover bugs, new security techniques emerge, users demand better performance, and communities propose new features.

Blockchain technology promises decentralized systems that can operate without relying on a central authority. But as blockchain networks attract more users, applications, and transactions, they face a fundamental challenge: how can they handle significantly more activity without becoming slow, expensive, or increasingly centralized?

Blockchain is often described as a decentralized technology, but not every blockchain is decentralized to the same degree. Some networks are highly distributed across thousands of participants worldwide, while others rely on a relatively small number of organizations to validate transactions and make decisions.