Blocks, and what finalized means
A block is a page in the chain's ledger. Every couple of seconds one of the validators collects the transactions that people have sent, writes them into a new block, and adds it to the end of the chain. Nothing that is written can be edited afterwards.
That is the whole idea. Blocks are how a chain keeps everyone's version of events identical without anyone being in charge of it.
Where to see them
The front page shows the most recent blocks as they arrive. Blockchain and then Blocks in the menu opens the full list, which goes back to the beginning of the chain.
The list is live. New blocks appear at the top on their own, and the Live button pauses that so a row does not slide away while you are reading it. Press it again to resume.
The filters narrow the list by validator, by block range or by date, and can hide blocks that contain no transactions.
What is on a block page
Most of it is background detail. These are the parts worth knowing.
| Field | What it means |
|---|---|
| Block number | Its position in the chain. Block 100 came right after block 99 |
| Timestamp | When it was produced |
| Validator | Which validator produced it |
| Transactions | How many transactions it contains, as a link to them |
| Block reward | What the validator earned for producing it |
| Burnt fees | The share of the fees in this block that was destroyed rather than paid out. See Fee burn |
| Gas used | How full the block was, out of the space available |
Block hash and parent hash are the fingerprints that chain the blocks together. Each block carries the fingerprint of the one before it, which is why you cannot alter an old block without every block after it no longer matching.
The rest, behind More details, is technical and safe to skip.
Finalized and unfinalized
Every block page carries one of two badges.
Unfinalized means the block is on the chain and, in all normal circumstances, will stay there. It is new enough that the network has not yet closed the door on it.
Finalized means that door is closed. The block is settled permanently and cannot be replaced, no matter what happens afterwards.
Blocks become finalized within a short time of being produced. For everyday amounts the difference rarely matters, because a transaction in an unfinalized block has essentially already happened. For a large amount, or when you are handing over something valuable in return, waiting for finalized is the careful thing to do.
Confirmations
On a transaction page you will see a number of confirmations. That is simply how many blocks have been added since the one your transaction is in. It counts up on its own and is another way of expressing the same idea: the more blocks stacked on top, the more settled the transaction is.
Why a block can be empty
Blocks are produced on a schedule, not on demand. If nobody sent anything during those few seconds, the validator produces an empty block anyway, and that is perfectly normal.
The catching-up banner
If a coloured bar says the explorer is a number of blocks behind, it means the chain has moved faster than the explorer could read it. The chain is fine, your transactions are fine, and the display catches up by itself.