<p>There are no magic math to understand for this: simply it was needed some target to let people calculate and mine with some difficulty having success after a certain time. The “lower than” has been chosen, but “greater than” some number or “comprised between “ a couple of number works in the same way. The “lower than” has the useful property that declaring a single parameter (the threshold) you tune all the miner on the target (i.e. 0 &lt; x &lt; threshold) and that as lower is the parameter as higher is the number of guess you should test before to find a good one. You need to define some interval because it is practically impossible to find a single number which when passed trough sha256 yields a certain target number value exactly.</p>

CC BY-SA 4.0
2022-05-14T10:17:33.063Z
2022-05-14T14:02:14.827Z
2022-05-14T14:02:14.827Z
Rick Park
<p>Target and Difficulty are separate concepts. You may want to take a look at this answer I wrote for another question: <a href="https://bitcoin.stackexchange.com/questions/113239/how-often-does-target-hash-change-and-how-to-find-it/113243#113243">How often does target hash change and how to find it?</a></p>

CC BY-SA 4.0
2022-04-14T00:40:27.723Z
2022-04-14T01:53:17.737Z
2022-04-14T01:53:17.737Z
Bitcoin_1o1
<p>I'd like to ask if someone can help explain this definition found on <a href="https://en.bitcoin.it/wiki/Target" rel="nofollow noreferrer">https://en.bitcoin.it/wiki/Target</a></p>
<p>&quot;The SHA-256 hash of a block's header must be lower than or equal to the current target for the block to be accepted by the network&quot;. I understand that target means difficulty. But I don't understand what the hash being lower than the target actually means.</p>
<p>I looked on youtube for explanations of target hash but they returned an investopedia definition.</p>
<p>Thank you in advance.</p>

CC BY-SA 4.0
2022-04-14T09:49:38.047Z
Does this answer your question? [How often does target hash change and how to find it?](https://bitcoin.stackexchange.com/questions/113239/how-often-does-target-hash-change-and-how-to-find-it). The hash is a number. Just like 33 is a number. The target is a number. Just like 76 is a number. We can see that a hash is less than a target just like we can see 33 is less than 76. `if hash < target { publish_block() } else { nonce++; continue loop }`
RedGrittyBrick
<hash><difficulty><sha256>
Why does SHA256 miner hash have to be lower than the current target 256bit hex?
HeyDoeFarm
# Why does SHA256 miner hash have to be lower than the current target 256bit hex?

(Asked by: username_0 on 2022-04-13)

I'd like to ask if someone can help explain this definition found on <https://en.bitcoin.it/wiki/Target>

"The SHA-256 hash of a block's header must be lower than or equal to the current target for the block to be accepted by the network". I understand that target means difficulty. But I don't understand what the hash being lower than the target actually means.

I looked on youtube for explanations of target hash but they returned an investopedia definition.

Thank you in advance.

**Tags:** hash, difficulty, sha256

> **Comments:**
> **username_1**: Does this answer your question? [How often does target hash change and how to find it?](https://bitcoin.stackexchange.com/questions/113239/how-often-does-target-hash-change-and-how-to-find-it). The hash is a number. Just like 33 is a number. The target is a number. Just like 76 is a number. We can see that a hash is less than a target just like we can see 33 is less than 76. `if hash < target { publish_block() } else { nonce++; continue loop }`  

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## 2 answers

### Answer by username_2 on 2022-05-14. Score: 0

There are no magic math to understand for this: simply it was needed some target to let people calculate and mine with some difficulty having success after a certain time. The “lower than” has been chosen, but “greater than” some number or “comprised between “ a couple of number works in the same way. The “lower than” has the useful property that declaring a single parameter (the threshold) you tune all the miner on the target (i.e. 0 < x < threshold) and that as lower is the parameter as higher is the number of guess you should test before to find a good one. You need to define some interval because it is practically impossible to find a single number which when passed trough sha256 yields a certain target number value exactly.


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### Answer by username_3 on 2022-04-14. Score: 0

Target and Difficulty are separate concepts. You may want to take a look at this answer I wrote for another question: [How often does target hash change and how to find it?](https://bitcoin.stackexchange.com/questions/113239/how-often-does-target-hash-change-and-how-to-find-it/113243#113243)


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