Block
A block is a portion of records that the network adds to the chain in one piece. Inside sit the header and the list of transactions, and finding one is what earning the reward means.
What a block is
A block has two parts. The first is the block header: a short set of fields holding the link to the previous block, the fingerprint of the transaction list, the time, the difficulty target and the number that gets iterated. The second is the transactions themselves. A miner runs through header variants until the hash comes out below the target.
Bitcoin turns out a block roughly once every ten minutes, which comes to about 144 blocks a day. Litecoin runs on a two and a half minute interval. Kaspa produces a block about once a second, and that changes what the network on your side has to deliver: the faster the blocks, the more the delay to the pool hurts.
Every block points back at the one before it, and that is where the word chain comes from. Changing an old record means recomputing every block after it, and that is as much work as the whole network has done in the meantime. This is exactly why confirmations carry weight: the deeper a transaction sits in the chain, the more expensive it becomes to rewrite.
A block you find does not put money in your hand right away. The reward matures after 100 confirmations, roughly seventeen hours on Bitcoin. In a pool you never notice this, because the pool pays out of its own funds sooner.
Quick reference table
| What is inside | the header and the list of transactions |
| Bitcoin interval | about 10 minutes, roughly 144 blocks a day |
| Litecoin | two and a half minutes |
| Kaspa | about one block per second |
| Reward maturity | 100 confirmations on Bitcoin |
What matters here for a miner
The miner's job is running through the header, not checking transactions. Checking is what network nodes do, so an ASIC keeps no copy of the chain and takes up none of your disk space.
A job for a new block arrives from the pool over Stratum, and every new job cancels the old one. The practical conclusion follows: the farther away the pool server sits, the more of your solutions arrive stale, and on networks with fast blocks that shows up most of all.
Transaction fees inside a block are part of the reward. On busy days they add a noticeable slice to the payout, and FPPS differs from PPS precisely in that it shares this extra.
An example in numbers
A day of Bitcoin is roughly 144 blocks of 3.125 BTC plus fees. An Antminer S21 at 200 TH/s in a network of about 950 EH/s has a claim on two ten millionths of that issuance, and running solo it would wait for its own block ninety years on average. In a pool the same share turns into a daily payout.
Related terms
Where to go next on the site
Coins
Algorithms
- SHA-256 algorithms
Numbers
Questions and answers
How many blocks a day does Bitcoin produce
About 144, because the network holds the interval near ten minutes. The exact count drifts, since difficulty adjusts with a lag.
Does an ASIC store the blockchain
No. The asic only runs through header variants, while the chain is stored and checked by network nodes. A miner needs no disk for that.
Why is my transaction not confirming
It is waiting its turn to get into a block. The higher the fee, the sooner it gets picked up. For a miner that is no trouble at all. It is where the extra slice of the reward comes from.
What is block height
Its sequential number counting from the very first one. Network events are counted by height, for example the Bitcoin halving every 210000 blocks.
How the terms connect
Every link in the chain is clickable. Orange marks where you are now.
Looking for an ASIC miner
The catalog holds 212 models. You can compare them by hashrate and by joules per terahash, then plug your own rate into the calculator and see what stays in your pocket.
Page written and checked by Denys Klimchuk. Updated .