> ## Documentation Index
> Fetch the complete documentation index at: https://docs.theblockchainlibrary.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Sidechain

> A sidechain is an independent blockchain that runs in parallel to a main chain (like Ethereum), connected by a two-way bridge. Unlike a rollup, a sidechain has its own consensus mechanism and set of validators, meaning it does not inherit the security of the main chain. If a side

# Sidechain

A sidechain is an independent blockchain that runs in parallel to a main chain (like Ethereum), connected by a two-way bridge. Unlike a rollup, a sidechain has its own consensus mechanism and set of validators, meaning it does not inherit the security of the main chain. If a sidechain fails or is compromised, the main chain remains unaffected, but the assets and activity on the sidechain may be at significant risk.

## Definition

A sidechain is an independent blockchain that runs in parallel to a main chain (like Ethereum), connected by a two-way bridge. Unlike a rollup, a sidechain has its own consensus mechanism and set of validators, meaning it does not inherit the security of the main chain. If a sidechain fails or is compromised, the main chain remains unaffected, but the assets and activity on the sidechain may be at significant risk.

## Simple explanation

A sidechain is like a separate, smaller amusement park built next to a famous one. You can use your ticket from the big park to go to the smaller one, but the smaller park has its own security guards and rules.

## Why it matters

Sidechains provide an alternative for applications that require extreme speed or flexibility that may not be available on the main chain. They offer a way to experiment with different governance models and consensus rules.

## How it works

Users transfer assets to a bridge, where they are locked on the main chain and minted as a representation on the sidechain. The sidechain operates independently using its own validators to process transactions. To move assets back, the user burns tokens on the sidechain to unlock the original funds on the main chain.

## Real-world example

The Gnosis Chain is a well-known example of a sidechain that operates alongside Ethereum.

## Advantages

* Customizable consensus rules
* Extremely high speed potential
* Independent network maintenance
* Increased transaction speed
* Lower transaction fees
* Customizable protocols

## Limitations

* Lacks mainnet security guarantees
* Bridge risks (asset lock/unlock)
* Requires separate trust assumptions
* Security depends on bridge
* Less secure than mainnet
* Risk of bridge hacks

## Common misconceptions

* Users often confuse sidechains with Layer 2 rollups; sidechains do not inherit Ethereum's security.
* Many believe sidechains are just as 'decentralized' as the main network, but they often have fewer validators.
* It is not the same as a layer-2 rollup.
* It does not inherit all security features of the parent chain.

## Related knowledge

* [Bridge](/generated/v2/glossary/bridge) — term
* [Consensus](/categories/consensus) — term
* [Ethereum](/categories/ethereum) — term
* [Interoperability](/categories/interoperability) — term
* [Layer 1](/generated/v2/glossary/layer-1) — term
* [Layer 2](/categories/layer-2) — term
* [Mainnet](/generated/v2/glossary/mainnet) — term
* [Polygon](/generated/v2/rpc/polygon-ankr) — term
* [Validator](/generated/v2/glossary/validator) — term

***

**Canonical knowledge ID:** `glossary:sidechain`