Term
Block explorer
A block explorer is a website that lets anyone look up the state of a blockchain — transactions, addresses, blocks, confirmations, and token balances — by querying the public ledger and rendering it in a browser.
Every public blockchain publishes its entire transaction history on-chain, but reading raw block data requires running a node. A block explorer is a website that runs those nodes for you and renders the state through a browser — you can paste a transaction hash and see its status, paste an address and see every transaction it ever made, paste a block number and see its contents.
Popular explorers by chain: mempool.space and blockstream.info for Bitcoin, Etherscan for Ethereum (and Arbiscan, Optimism explorer, Basescan, Polygonscan for the L2s and Polygon), Tronscan for TRON, BscScan for BNB Smart Chain, Solscan for Solana. Each shows roughly the same information: transaction status, confirmations, fees, addresses involved, and any smart-contract interactions.
The main practical use is troubleshooting a swap or transfer. If your swap is stuck at "Confirming," open a block explorer for the source chain, paste the transaction hash you were given at deposit time, and check how many confirmations the network has processed. If the count is climbing normally, the swap is fine; if the transaction is not visible at all, something is wrong with the deposit.
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