System chains

Chromia is divided into multiple blockchains to achieve horizontal scalability. In this model, each node only needs to work with data related to its corresponding blockchains. This architecture increases scalability and simplifies updates, as an update of a single blockchain does not affect others. The overall system consists of several system blockchains, which are essential for Chromia functionality as well as several dapp blockchains that are specific to particular applications.

System chain	Description
Root chain	The root chain is needed for thin clients to validate any data within Chromia without downloading the entire blockchain.
Directory chain	A dapp for managing all blockchains in the network, including itself. It stores all the needed information to run the network, such as a list of providers and nodes and configurations (code) of all blockchains on the Chromia network. It helps to synchronize configuration changes between nodes.
Token root chain	The token root chain keeps track of token distribution between other chains.
Anchoring chain	The anchoring chain records hashes of blocks of other chains. This feature makes it possible to detect consensus failures. In case of a consensus failure, blocks anchored in the anchoring chain take precedence over different versions of blocks. The anchoring chain is itself anchored in Bitcoin and Ethereum blockchains.