Blockchain//Wallet//Metamask

- Browser extension that injects an `ethereum` object into every web page's DOM.

Browser extension that injects an ethereum object into every web page's DOM.

ethereum.request({ method: 'eth_requestAccounts' }) triggers Metamask's approval popup.

NOT a node. It's a light client that delegates blockchain queries to an RPC endpoint (default: Infura)

Password encrypts the seed phrase in browser local storage. Unlock = decrypt → derive keys on the fly.

Switching networks = changing RPC URL + chainId. Tells Metamask where to send and what chain to sign for.