A blockchain is a shared digital ledger enabling users to securely record transactions and share information in a tamper-resistant manner. But, how can you publicly verify and audit transactions in blockchain? How can you see real-time data on blocks, transactions, miners, accounts, and other on-chain activity? For someone in the field of blockchain, it is crucial to understand how transactions happen and are recorded in blockchain. Here’s a simple transaction life cycle of a blockchain transaction - 

You send crypto tokens (money) by signing a secure digital message through your private key. This transaction message is then broadcased to a group of computers (nodes) on the blockchain network. The computers temporarily store your message in a waiting area (mempool). The digital bookkeepers (miners) select transactions from this mempool and add them to a block as a permanent record on the blockchain. Once added, the block is broadcasted to all the connected nodes with the state that the transaction has been confirmed. It becomes an immutable part of the transaction history. The more confirmations, the more secure and final your transaction is.

Now, once the transaction is timestamped and recorded in the blockchain, anyone can view the transaction using a block explorer. A block explorer is an online read-only tool that enables the public to search for real-time and historical information about a blockchain, including data related to blocks, transactions, addresses, and more. It operates much like a search engine in terms of its functionality. Let’s take an example of Etherscan, a blockchain explorer for the Ethereum blockchain and is used to review transactions.

Open www.etherscan.io from the browser. It will open a landing page where you can search and review transactions. You can either enter your wallet address or a unique transaction ID to review transactions in Ethereum blockchain. You can read my previous article on opening a blockchain wallet here - https://www.esatya.io/blogs/experiencing-blockchain 

If you search for a wallet address in Etherscan, you can see the overall wallet balance in ETH and its USD value along with a list of transactions done through the wallet in the overview along with the transactions done from or to that wallet address. Remember wallet addresses are pseudonymous - transactions on the blockchain are visible and traceable but users' identities remain anonymous.

You can also review Transaction Details in that wallet. Once you open the transactions in that wallet, you will see the following information - 

- The Transaction Hash serves as the identification for the transaction, with each transaction having its own distinct identifier.

- Status indicates whether the transaction was successful, pending, or failed.

- Block indicates the number of blocks that have been recorded in the blockchain.

- Timestamp is the date and time when the transaction occurred.

- From and To are the wallet addresses from where the funds were transacted. 

- Value shows the amount transferred and the Transaction Fee shows the cost of the transaction. (Gas fee)

In conclusion, once transactions are time stamped and recorded in the blockchain, their unalterable nature ensures transparency and public accessibility through block explorers. This immutability not only upholds the integrity of the system but also facilitates an efficient auditable process for reconciling transactions.