Ethernal is a block explorer for private EVM-based chains, similar to Etherscan. Once you are set up, you will be able to browse blocks, transactions, accounts, and contracts. But also read contract variables, decode function calls and events.
You can connect Ethernal to any chain, whether you are running it locally or on a remote server.
Ethernal works with a CLI that listens to blocks and transactions and synchronizes them to your dashboard.
In order to decode contract variables data, you can also synchronize artifacts data through the CLI for Truffle projects or a dedicated plugin for Hardhat projects.
If you want to know more about what data is synchronized and why, the FAQ can help you.