---
# System prepended metadata

title: Cosmos Ecosystem

---

# Blockchain Knowledge Share

## Cosmos Ecosystem

[_Cosmos Network_](https://cosmos.network) is an _Internet of Blockchain_ where multiple blockchains, called _app-chains_, co-exist and communicate with each other over IBC.

Cosmos Network does not have any main or centralized blockchain - but [_CosmosHub_](https://cosmos.network/intro) is the first and politically popular blockchain in the network. CosmosHub is secured by [\$ATOM](https://www.coinbase.com/price/cosmos) token. CosmosHub works toward to become the economic center of Cosmos Network, but not exclusively.

Cosmos Network leverages [Cosmos-SDK](https://docs.cosmos.network) to build app-chains - which are essentially sovereign blockchains. These blockchains are powered by [CometBFT](https://docs.cometbft.com) - a pBFT consensus protocol implementation. Cosmos-SDK is bundled with [IBC](https://ibcprotocol.org) implementation, so your app-chains can communicate with other app-chains from the start.

### Cosmos-SDK - ABCI application on top of CometBFT

Cosmos-SDK has two components. One is CometBFT and the other is Blockchain Application itself.

The application contains multiple modules and these modules can communicate with each other. The default application already includes many modules with useful blockchain logic e.g. Staking (for PoS), Banking etc. IBC implementation also resides in a module.

You can extend this default blockchain application with your own application logic in separate modules and customize it as per your requirement. This is why Cosmos-SDK is the go-to tool if you are prototyping your own blockchain application.

General Docs: https://docs.cosmos.network

### CometBFT - Tendermint consensus implementation

General Docs: https://docs.cometbft.com
Consensus Overview: https://docs.cometbft.com/v0.38/introduction/#consensus-overview
Application BlockChain Interface (ABCI): https://docs.cometbft.com/v0.38/guides/go#13-writing-a-cometbft-application


### Inter-Blockchain Communication (IBC)

Website: https://ibcprotocol.org

Formal Analysis of IBC: [PDF](https://lcs.ios.ac.cn/~zxy/papers/c23icnp-wei.pdf)

## Ethereum

- L0, L1, L2, L3: https://bitpowr.com/blog/blockchain-layers-l0-l1-l2-l3

![](https://hackmd.io/_uploads/rJQWFZE-a.png)

- Rollups: https://coinmarketcap.com/academy/article/optimistic-rollups-vs-zk-rollups-the-ultimate-comparison