In February 2021, Ethereum layer 2 scaling solution Matic Network rebranded as Polygon—an interoperable blockchain scaling framework.
What is Polygon?
Previously known as Matic Network, Polygon is a framework for building interconnected blockchain networks. It seeks to address some of Ethereum's major limitations—including its throughput, poor user experience (high speed and delayed transactions), and lack of community governance—using a novel sidechain solution.
Rather than being a simple scaling solution like its predecessor Matic Network—which uses a technology known as Plasma to process transactions off-chain before finalizing them on the Ethereum main chain—Polygon is designed to be an entire platform designed for launching interoperable blockchains.
Through Polygon, developers can launch preset blockchain networks with attributes tailored to their needs. These can be further customized with a growing range of modules, which allow developers to create sovereign blockchains with more specific functionality.
How does Polygon work?
Polygon's architecture can best be defined as a four-layer system composed of the Ethereum layer, security layer, Polygon networks layer, and execution layer.
The Ethereum layer is essentially a set of smart contracts which are implemented on Ethereum. These smart contracts handle things like transaction finality, staking, and communication between Ethereum and the various Polygon chains.
The security layer runs side by side with Ethereum and provides a "validators as a service" role which allows chains to benefit from an additional layer of security. Both the Ethereum and Security layers are optional.
Beyond this, there are two mandatory layers. The first is the Polygon networks layer, which is the ecosystem of blockchain networks built on Polygon. Each of these has its own community and is responsible for handling local consensus and producing blocks. The second is the Execution layer, which is Polygon's Ethereum Virtual Machine (EVM) implementation used for executing smart contracts.
Chains launched on Polygon are capable of communicating both with one another and with the Ethereum main chain thanks to Polygon's arbitrary message passing capabilities. This will enable a variety of new use-cases, such as interoperable decentralized applications (dapps) and the simple exchange of value between diverse platforms.
Polygon: Ethereum's Internet of Blockchains
Polygon is designed to facilitate a future where different blockchains no longer operate as closed-off siloes and proprietary communities, but instead as networks that fit into a broader interconnected landscape. Its long-term goal is to enable an open, borderless world in which users can seamlessly interact with decentralized products and services without first having to navigate through intermediaries or walled gardens. It aims to create a hub that different blockchains can easily plug into, while simultaneously overcoming some of their individual limitations—such as high fees, poor scalability, and limited security.
Polygon uses a variety of technologies to achieve this expanded vision, these include:
POS Chain: Polygon's main chain is an Ethereum sidechain known as the Matic POS Chain, which adds a proof-of-stake (POS) security layer to blockchains launched on Polygon.
Plasma Chains: Polygon makes use of a scaling technology known as Plasma to move assets between the root chain and child chains via Plasma bridges.
ZK-rollups: An alternative scaling solution used to bundle a large number of transfers off-chain into a single transaction, using zero-knowledge proofs for the final public record on the Ethereum main chain.
Optimistic rollups: A solution that runs on top of Ethereum to facilitate near-instant transactions through the use of "fraud proofs".
As you might have noticed, Polygon intends to incorporate more than one scaling solution, in keeping with its goal of minimizing barriers to entry by attempting to reduce transaction fees to a bare minimum. By taking a multi-pronged approach to the issue of scaling, Polygon is hedging its bets, should any other scaling solution fail to accomplish its purpose.
What’s so special about it?
The Polygon project is one of the more recent attempts at blockchain interoperability and scaling, and is designed to address some of the perceived limitations of interoperability projects such as Polkadot and Cosmos.
For one, it’s compatible with the Ethereum Virtual Machine, which makes it approachable to those accustomed to building apps on Ethereum and programming in Solidity; its rival Cosmos uses a WASM-based virtual machine.