How On-Chain Data Works: Blocks, Transactions, and Explorers
What a block explorer actually shows you, and how to read one.
Every transaction on a public blockchain is recorded in a block. Each block references the one before it via a cryptographic hash, which is what makes the chain hard to rewrite: changing an old block would invalidate every block after it.
A block explorer is a website that indexes this data and lets you search it. You can look up an address to see its balance and history, a transaction hash to see whether it succeeded, or a block number to see everything included at that height.
For educational purposes, exploring the chain is one of the best ways to learn. Send a small transaction, then find it in the explorer. You'll see the sender, receiver, value, fee, block number, and any contract calls involved.
The data is public and immutable. That transparency is powerful, but it also means addresses and their histories can be tracked. Privacy on public chains is a design consideration, not a default.