<p>There is a nice explanation on how it works in the bitcoin wiki, bitcoin.it :</p>
<blockquote>
<p>A block chain is a transaction database shared by all nodes participating in a system based on the Bitcoin protocol. A full copy of a currency's block chain contains every transaction ever executed in the currency. With this information, one can find out how much value belonged to each address at any point in history.</p>
<p>Every block contains a hash of the previous block. This has the effect of creating a chain of blocks from the genesis block to the current block. Each block is guaranteed to come after the previous block chronologically because the previous block's hash would otherwise not be known. Each block is also computationally impractical to modify once it has been in the chain for a while because every block after it would also have to be regenerated. These properties are what make double-spending of bitcoins very difficult. The block chain is the main innovation of Bitcoin.</p>
<p>From <a href="https://en.bitcoin.it/wiki/Block_chain" rel="nofollow noreferrer">https://en.bitcoin.it/wiki/Block_chain</a></p>
</blockquote>

CC BY-SA 3.0
2014-02-23T02:33:41.257Z
2014-02-23T02:33:41.257Z
2020-06-16T11:10:03.350Z
Mark
<p>I am trying to better understand the fundamentals of the BLOCKCHAIN. 
I am not technical and am hoping someone can offer up an explanation in LAY TERMS.  </p>

<p>Thanks in advance.</p>

CC BY-SA 3.0
2014-02-23T02:35:04.530Z
possible duplicate of [Can someone explain how the Bitcoin Blockchain works?](http://bitcoin.stackexchange.com/q/12427/5406), [What is the Blockchain?](http://bitcoin.stackexchange.com/q/168/5406)
Murch
CC BY-SA 3.0
2014-02-23T02:40:44.923Z
related: [Why is blockchain necessary?](http://bitcoin.stackexchange.com/q/9293/5406)
Murch
<blockchain><block>
Help understanding the blockchain
Bitnewbie63
# Help understanding the blockchain

(Asked by: username_0 on 2014-02-23)

I am trying to better understand the fundamentals of the BLOCKCHAIN.
I am not technical and am hoping someone can offer up an explanation in LAY TERMS.

Thanks in advance.

**Tags:** blockchain, block

> **Comments:**
> **username_1**: possible duplicate of [Can someone explain how the Bitcoin Blockchain works?](http://bitcoin.stackexchange.com/q/12427/5406), [What is the Blockchain?](http://bitcoin.stackexchange.com/q/168/5406)  
> **username_1**: related: [Why is blockchain necessary?](http://bitcoin.stackexchange.com/q/9293/5406)  

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## 1 answers

### Answer by username_2 on 2014-02-23. Score: 0

There is a nice explanation on how it works in the bitcoin wiki, bitcoin.it :

> A block chain is a transaction database shared by all nodes participating in a system based on the Bitcoin protocol. A full copy of a currency's block chain contains every transaction ever executed in the currency. With this information, one can find out how much value belonged to each address at any point in history.
>
> Every block contains a hash of the previous block. This has the effect of creating a chain of blocks from the genesis block to the current block. Each block is guaranteed to come after the previous block chronologically because the previous block's hash would otherwise not be known. Each block is also computationally impractical to modify once it has been in the chain for a while because every block after it would also have to be regenerated. These properties are what make double-spending of bitcoins very difficult. The block chain is the main innovation of Bitcoin.
>
> From <https://en.bitcoin.it/wiki/Block_chain>


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