# Blockchain Notes and important links ### Public Chains: (GUI- Metamask, API- Infura) * Mainnet * Rinkeby * Ropsten * Kovan * Goerli ### Local chains: (GUI - remix Javascript-VM, API - truffle) * localhost:8545 for truffle framework ### Concepts: * Nonce * Account Address or Wallet Address * Contract Address * Public key, private key * ABI, Bytecode * Solidity programme language (OOPS based) * Swapping token * ERC20 and other token standards * Gas price and its calculation * Fee for Transaction * Burn token * Mining in blockchain ### Libraries, tools involved for NodeJS blockchain layer * web3 * ethereumjs-tx * ethereumjs-wallet * keythereum ### Selected Chain for testing - Rinkeby: Links: * Chain stats: https://www.rinkeby.io/#stats * Chain Explorer: https://rinkeby.etherscan.io ![](https://i.imgur.com/fra5wQ1.jpg)