A block explorer is your window into the blockchain—think of it as a public ledger where every transaction lives permanently. When you paste a transaction hash (txn ID) into a block explorer like Solscan for Solana or Etherscan for Ethereum, you get the full truth: who sent what, to whom, and exactly when it happened. Look for the "from" and "to" addresses, the amount transferred, and the gas or transaction fees paid. If you're checking a token transfer or smart contract interaction, the explorer shows you which contract was called and what state changed. This is how you catch mistakes before they're irreversible—scammers can't fake what's on-chain. Pay attention to the transaction status: confirmed, failed, or pending. A failed transaction still costs you fees, so if something went wrong, the explorer tells you why by showing the error message. You can also see the exact block number and timestamp, which proves when your transaction actually settled. Pro tip: learning to read an explorer means you never have to blindly trust someone's screenshot again.