<h1>What's in a Block?</h1>

<p>A block is a data structure that contains transactions as well as metadata about the block. All transactions must be included in a valid block in order to be considered final. All full nodes on the network will store a copy of the block in order to validate new transactions and share the data with other nodes.</p>

<h2>Block Structure</h2>

<pre><code>$ bitcoin-cli -regtest getblockhash 0
0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206

$ bitcoin-cli -regtest getblock 0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206 0
</code></pre>

<p><code>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</code></p>

<p>This is the genesis block for the regtest network. It is hard coded in Bitcoin core and is the first block, so it does not reference any previous blocks. It also contains a message from Satoshi Nakamoto, the pseudonymous creator of Bitcoin in the coinbase scriptSig.</p>

<p>{block header} {transaction counter} {transactions}</p>

<h3>Block Header</h3>

<p>{version 4B} {previous block hash 32B} {merkle root hash 32B} {time 4B} {bits 4B} {nonce 4B}</p>

<ul>
<li>Version (4 Bytes) - Block format version.</li>
<li>Previous Block Hash (32 Bytes) - The hash of the preceding block. This is important to include in the header because the hash of the block is calculated from the header, and thus depends on the value of the previous block, linking each new block to the last. This is the link in the chain of the blockchain.</li>
<li>Merkle Root Hash (32 Bytes) - The hash of the merkle tree root of all transactions in the block. If any transaction is changed, removed, or reordered, it will change the merkle root hash. This is what locks all of the transactions in the block.</li>
<li>Time (4 Bytes) - Timestamp in Unix Time {TODO: provide link} (seconds). Since the clocks of each node around the world is not guaranteed to be synchronized, this is just required to be within {TODO} of the rest of the network.</li>
<li>Bits (4 Bytes) - Target hash value in <a href="https://bitcoin.org/en/developer-reference#target-nbits" rel="nofollow noreferrer">Compact Format</a>. The block hash must be equal to or less than this value in order to be considered valid.</li>
<li>Nonce (4 Bytes) - Can be any 4 Byte value, and is continuously changed while mining until a valid block hash is found.</li>
</ul>

<p><code>01000000 0000000000000000000000000000000000000000000000000000000000000000 3ba3edfd7a7b12b27ac72c3e67768f617fc81bc3888a51323a9fb8aa4b1e5e4a dae5494d ffff7f20 02000000</code></p>

<p><strong>Block Header:</strong></p>

<ul>
<li>Version - <code>01000000</code> (1)</li>
<li>Previous Block Hash - <code>0000000000000000000000000000000000000000000000000000000000000000</code></li>
<li>Merkle Root Hash - <code>3ba3edfd7a7b12b27ac72c3e67768f617fc81bc3888a51323a9fb8aa4b1e5e4a</code></li>
<li>Time - <code>dae5494d</code> (1296688602 Wednesday, February 2, 2011 11:16:42 PM GMT)</li>
<li>Bits - <code>ffff7f20</code> (<code>7fffff0000000000000000000000000000000000000000000000000000000000</code>)</li>
<li>Nonce - <code>02000000</code> (2)</li>
</ul>

<p><strong>Note:</strong> Remember Bitcoin uses little endian format, which may seem backwards. You can use the provided tool <code>$ reverse_endian {hex}</code> to reverse the endianess of a hex string.</p>

<h3>Transaction Counter</h3>

<p><code>01</code> (1) Transaction in the block</p>

<ul>
<li>Transaction Counter (Variable Length) - Number of transactions in the block represented as a <a href="https://en.bitcoin.it/wiki/Protocol_documentation#Variable_length_integer" rel="nofollow noreferrer">Variable Length Integer</a>.</li>
</ul>

<h3>Transactions</h3>

<p>See <a href="https://en.bitcoin.it/wiki/Transaction" rel="nofollow noreferrer">https://en.bitcoin.it/wiki/Transaction</a></p>

<p><strong>See also:</strong></p>

<ul>
<li><a href="https://en.bitcoin.it/wiki/Block" rel="nofollow noreferrer">https://en.bitcoin.it/wiki/Block</a></li>
<li><a href="https://en.bitcoin.it/wiki/Block_hashing_algorithm" rel="nofollow noreferrer">https://en.bitcoin.it/wiki/Block_hashing_algorithm</a></li>
</ul>

CC BY-SA 4.0
2018-12-14T16:09:30.013Z
thanks so much,  I will you read more documents from your recommended links
Freewind
CC BY-SA 4.0
2018-12-14T15:42:58.003Z
2018-12-14T15:42:58.003Z
JBaczuk
<p>We can get bitcoin block data as JSON by command <code>bitcoin-cli getblock &lt;hash&gt; 2</code>, following is one for height <code>100000</code>:</p>

<pre><code>{
    "hash": "000000000003ba27aa200b1cecaad478d2b00432346c3f1f3986da1afd33e506",
    "confirmations": 135485,
    "strippedsize": 957,
    "size": 957,
    "weight": 3828,
    "height": 100000,
    "version": 1,
    "versionHex": "00000001",
    "merkleroot": "f3e94742aca4b5ef85488dc37c06c3282295ffec960994b2c0d5ac2a25a95766",
    "tx": [{
        "txid": "8c14f0db3df150123e6f3dbbf30f8b955a8249b62ac1d1ff16284aefa3d06d87",
        "hash": "8c14f0db3df150123e6f3dbbf30f8b955a8249b62ac1d1ff16284aefa3d06d87",
        "version": 1,
        "size": 135,
        "vsize": 135,
        "weight": 540,
        "locktime": 0,
        "vin": [{
            "coinbase": "044c86041b020602",
            "sequence": 4294967295
        }],
        "vout": [{
            "value": 50,
            "n": 0,
            "scriptPubKey": {
                "asm": "041b0e8c2567c12536aa13357b79a073dc4444acb83c4ec7a0e2f99dd7457516c5817242da796924ca4e99947d087fedf9ce467cb9f7c6287078f801df276fdf84 OP_CHECKSIG",
                "hex": "41041b0e8c2567c12536aa13357b79a073dc4444acb83c4ec7a0e2f99dd7457516c5817242da796924ca4e99947d087fedf9ce467cb9f7c6287078f801df276fdf84ac",
                "reqSigs": 1,
                "type": "pubkey",
                "addresses": ["1HWqMzw1jfpXb3xyuUZ4uWXY4tqL2cW47J"]
            }
        }],
        "hex": "01000000010000000000000000000000000000000000000000000000000000000000000000ffffffff08044c86041b020602ffffffff0100f2052a010000004341041b0e8c2567c12536aa13357b79a073dc4444acb83c4ec7a0e2f99dd7457516c5817242da796924ca4e99947d087fedf9ce467cb9f7c6287078f801df276fdf84ac00000000"
    }, {
        "txid": "fff2525b8931402dd09222c50775608f75787bd2b87e56995a7bdd30f79702c4",
        "hash": "fff2525b8931402dd09222c50775608f75787bd2b87e56995a7bdd30f79702c4",
        "version": 1,
        "size": 259,
        "vsize": 259,
        "weight": 1036,
        "locktime": 0,
        "vin": [{
            "txid": "87a157f3fd88ac7907c05fc55e271dc4acdc5605d187d646604ca8c0e9382e03",
            "vout": 0,
            "scriptSig": {
                "asm": "3046022100c352d3dd993a981beba4a63ad15c209275ca9470abfcd57da93b58e4eb5dce82022100840792bc1f456062819f15d33ee7055cf7b5ee1af1ebcc6028d9cdb1c3af7748[ALL] 04f46db5e9d61a9dc27b8d64ad23e7383a4e6ca164593c2527c038c0857eb67ee8e825dca65046b82c9331586c82e0fd1f633f25f87c161bc6f8a630121df2b3d3",
                "hex": "493046022100c352d3dd993a981beba4a63ad15c209275ca9470abfcd57da93b58e4eb5dce82022100840792bc1f456062819f15d33ee7055cf7b5ee1af1ebcc6028d9cdb1c3af7748014104f46db5e9d61a9dc27b8d64ad23e7383a4e6ca164593c2527c038c0857eb67ee8e825dca65046b82c9331586c82e0fd1f633f25f87c161bc6f8a630121df2b3d3"
            },
            "sequence": 4294967295
        }],
        "vout": [{
            "value": 5.56,
            "n": 0,
            "scriptPubKey": {
                "asm": "OP_DUP OP_HASH160 c398efa9c392ba6013c5e04ee729755ef7f58b32 OP_EQUALVERIFY OP_CHECKSIG",
                "hex": "76a914c398efa9c392ba6013c5e04ee729755ef7f58b3288ac",
                "reqSigs": 1,
                "type": "pubkeyhash",
                "addresses": ["1JqDybm2nWTENrHvMyafbSXXtTk5Uv5QAn"]
            }
        }, {
            "value": 44.44,
            "n": 1,
            "scriptPubKey": {
                "asm": "OP_DUP OP_HASH160 948c765a6914d43f2a7ac177da2c2f6b52de3d7c OP_EQUALVERIFY OP_CHECKSIG",
                "hex": "76a914948c765a6914d43f2a7ac177da2c2f6b52de3d7c88ac",
                "reqSigs": 1,
                "type": "pubkeyhash",
                "addresses": ["1EYTGtG4LnFfiMvjJdsU7GMGCQvsRSjYhx"]
            }
        }],
        "hex": "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"
    }, {
        "txid": "6359f0868171b1d194cbee1af2f16ea598ae8fad666d9b012c8ed2b79a236ec4",
        "hash": "6359f0868171b1d194cbee1af2f16ea598ae8fad666d9b012c8ed2b79a236ec4",
        "version": 1,
        "size": 257,
        "vsize": 257,
        "weight": 1028,
        "locktime": 0,
        "vin": [{
            "txid": "cf4e2978d0611ce46592e02d7e7daf8627a316ab69759a9f3df109a7f2bf3ec3",
            "vout": 1,
            "scriptSig": {
                "asm": "30440220032d30df5ee6f57fa46cddb5eb8d0d9fe8de6b342d27942ae90a3231e0ba333e02203deee8060fdc70230a7f5b4ad7d7bc3e628cbe219a886b84269eaeb81e26b4fe[ALL] 04ae31c31bf91278d99b8377a35bbce5b27d9fff15456839e919453fc7b3f721f0ba403ff96c9deeb680e5fd341c0fc3a7b90da4631ee39560639db462e9cb850f",
                "hex": "4730440220032d30df5ee6f57fa46cddb5eb8d0d9fe8de6b342d27942ae90a3231e0ba333e02203deee8060fdc70230a7f5b4ad7d7bc3e628cbe219a886b84269eaeb81e26b4fe014104ae31c31bf91278d99b8377a35bbce5b27d9fff15456839e919453fc7b3f721f0ba403ff96c9deeb680e5fd341c0fc3a7b90da4631ee39560639db462e9cb850f"
            },
            "sequence": 4294967295
        }],
        "vout": [{
            "value": 0.01,
            "n": 0,
            "scriptPubKey": {
                "asm": "OP_DUP OP_HASH160 b0dcbf97eabf4404e31d952477ce822dadbe7e10 OP_EQUALVERIFY OP_CHECKSIG",
                "hex": "76a914b0dcbf97eabf4404e31d952477ce822dadbe7e1088ac",
                "reqSigs": 1,
                "type": "pubkeyhash",
                "addresses": ["1H8ANdafjpqYntniT3Ddxh4xPBMCSz33pj"]
            }
        }, {
            "value": 2.99,
            "n": 1,
            "scriptPubKey": {
                "asm": "OP_DUP OP_HASH160 6b1281eec25ab4e1e0793ff4e08ab1abb3409cd9 OP_EQUALVERIFY OP_CHECKSIG",
                "hex": "76a9146b1281eec25ab4e1e0793ff4e08ab1abb3409cd988ac",
                "reqSigs": 1,
                "type": "pubkeyhash",
                "addresses": ["1Am9UTGfdnxabvcywYG2hvzr6qK8T3oUZT"]
            }
        }],
        "hex": "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"
    }, {
        "txid": "e9a66845e05d5abc0ad04ec80f774a7e585c6e8db975962d069a522137b80c1d",
        "hash": "e9a66845e05d5abc0ad04ec80f774a7e585c6e8db975962d069a522137b80c1d",
        "version": 1,
        "size": 225,
        "vsize": 225,
        "weight": 900,
        "locktime": 0,
        "vin": [{
            "txid": "f4515fed3dc4a19b90a317b9840c243bac26114cf637522373a7d486b372600b",
            "vout": 0,
            "scriptSig": {
                "asm": "3046022100bb1ad26df930a51cce110cf44f7a48c3c561fd977500b1ae5d6b6fd13d0b3f4a022100c5b42951acedff14abba2736fd574bdb465f3e6f8da12e2c5303954aca7f78f3[ALL] 04a7135bfe824c97ecc01ec7d7e336185c81e2aa2c41ab175407c09484ce9694b44953fcb751206564a9c24dd094d42fdbfdd5aad3e063ce6af4cfaaea4ea14fbb",
                "hex": "493046022100bb1ad26df930a51cce110cf44f7a48c3c561fd977500b1ae5d6b6fd13d0b3f4a022100c5b42951acedff14abba2736fd574bdb465f3e6f8da12e2c5303954aca7f78f3014104a7135bfe824c97ecc01ec7d7e336185c81e2aa2c41ab175407c09484ce9694b44953fcb751206564a9c24dd094d42fdbfdd5aad3e063ce6af4cfaaea4ea14fbb"
            },
            "sequence": 4294967295
        }],
        "vout": [{
            "value": 0.01,
            "n": 0,
            "scriptPubKey": {
                "asm": "OP_DUP OP_HASH160 39aa3d569e06a1d7926dc4be1193c99bf2eb9ee0 OP_EQUALVERIFY OP_CHECKSIG",
                "hex": "76a91439aa3d569e06a1d7926dc4be1193c99bf2eb9ee088ac",
                "reqSigs": 1,
                "type": "pubkeyhash",
                "addresses": ["16FuTPaeRSPVxxCnwQmdyx2PQWxX6HWzhQ"]
            }
        }],
        "hex": "01000000010b6072b386d4a773235237f64c1126ac3b240c84b917a3909ba1c43ded5f51f4000000008c493046022100bb1ad26df930a51cce110cf44f7a48c3c561fd977500b1ae5d6b6fd13d0b3f4a022100c5b42951acedff14abba2736fd574bdb465f3e6f8da12e2c5303954aca7f78f3014104a7135bfe824c97ecc01ec7d7e336185c81e2aa2c41ab175407c09484ce9694b44953fcb751206564a9c24dd094d42fdbfdd5aad3e063ce6af4cfaaea4ea14fbbffffffff0140420f00000000001976a91439aa3d569e06a1d7926dc4be1193c99bf2eb9ee088ac00000000"
    }],
    "time": 1293623863,
    "mediantime": 1293622620,
    "nonce": 274148111,
    "bits": "1b04864c",
    "difficulty": 14484.1623612254,
    "chainwork": "0000000000000000000000000000000000000000000000000644cb7f5234089e",
    "nTx": 4,
    "previousblockhash": "000000000002d01c1fccc21636b607dfd930d31d01c3a62104612a1719011250",
    "nextblockhash": "00000000000080b66c911bd5ba14a74260057311eaeb1982802f7010f1a9f090"
}
</code></pre>

<p>I read some articles about the structure and fields of bitcoin block data, but I can't find documents to explain every fields clearly and in detail. </p>

<p>Anyone can give me some detailed information about the fields, or recommend some articles or books?</p>

<block>
Explanation of a block's fields one by one?
Freewind
# Explanation of a block's fields one by one?

(Asked by: username_0 on 2018-12-14)

We can get bitcoin block data as JSON by command `bitcoin-cli getblock <hash> 2`, following is one for height `100000`:

```
{
    "hash": "000000000003ba27aa200b1cecaad478d2b00432346c3f1f3986da1afd33e506",
    "confirmations": 135485,
    "strippedsize": 957,
    "size": 957,
    "weight": 3828,
    "height": 100000,
    "version": 1,
    "versionHex": "00000001",
    "merkleroot": "f3e94742aca4b5ef85488dc37c06c3282295ffec960994b2c0d5ac2a25a95766",
    "tx": [{
        "txid": "8c14f0db3df150123e6f3dbbf30f8b955a8249b62ac1d1ff16284aefa3d06d87",
        "hash": "8c14f0db3df150123e6f3dbbf30f8b955a8249b62ac1d1ff16284aefa3d06d87",
        "version": 1,
        "size": 135,
        "vsize": 135,
        "weight": 540,
        "locktime": 0,
        "vin": [{
            "coinbase": "044c86041b020602",
            "sequence": 4294967295
        }],
        "vout": [{
            "value": 50,
            "n": 0,
            "scriptPubKey": {
                "asm": "041b0e8c2567c12536aa13357b79a073dc4444acb83c4ec7a0e2f99dd7457516c5817242da796924ca4e99947d087fedf9ce467cb9f7c6287078f801df276fdf84 OP_CHECKSIG",
                "hex": "41041b0e8c2567c12536aa13357b79a073dc4444acb83c4ec7a0e2f99dd7457516c5817242da796924ca4e99947d087fedf9ce467cb9f7c6287078f801df276fdf84ac",
                "reqSigs": 1,
                "type": "pubkey",
                "addresses": ["1HWqMzw1jfpXb3xyuUZ4uWXY4tqL2cW47J"]
            }
        }],
        "hex": "01000000010000000000000000000000000000000000000000000000000000000000000000ffffffff08044c86041b020602ffffffff0100f2052a010000004341041b0e8c2567c12536aa13357b79a073dc4444acb83c4ec7a0e2f99dd7457516c5817242da796924ca4e99947d087fedf9ce467cb9f7c6287078f801df276fdf84ac00000000"
    }, {
        "txid": "fff2525b8931402dd09222c50775608f75787bd2b87e56995a7bdd30f79702c4",
        "hash": "fff2525b8931402dd09222c50775608f75787bd2b87e56995a7bdd30f79702c4",
        "version": 1,
        "size": 259,
        "vsize": 259,
        "weight": 1036,
        "locktime": 0,
        "vin": [{
            "txid": "87a157f3fd88ac7907c05fc55e271dc4acdc5605d187d646604ca8c0e9382e03",
            "vout": 0,
            "scriptSig": {
                "asm": "3046022100c352d3dd993a981beba4a63ad15c209275ca9470abfcd57da93b58e4eb5dce82022100840792bc1f456062819f15d33ee7055cf7b5ee1af1ebcc6028d9cdb1c3af7748[ALL] 04f46db5e9d61a9dc27b8d64ad23e7383a4e6ca164593c2527c038c0857eb67ee8e825dca65046b82c9331586c82e0fd1f633f25f87c161bc6f8a630121df2b3d3",
                "hex": "493046022100c352d3dd993a981beba4a63ad15c209275ca9470abfcd57da93b58e4eb5dce82022100840792bc1f456062819f15d33ee7055cf7b5ee1af1ebcc6028d9cdb1c3af7748014104f46db5e9d61a9dc27b8d64ad23e7383a4e6ca164593c2527c038c0857eb67ee8e825dca65046b82c9331586c82e0fd1f633f25f87c161bc6f8a630121df2b3d3"
            },
            "sequence": 4294967295
        }],
        "vout": [{
            "value": 5.56,
            "n": 0,
            "scriptPubKey": {
                "asm": "OP_DUP OP_HASH160 c398efa9c392ba6013c5e04ee729755ef7f58b32 OP_EQUALVERIFY OP_CHECKSIG",
                "hex": "76a914c398efa9c392ba6013c5e04ee729755ef7f58b3288ac",
                "reqSigs": 1,
                "type": "pubkeyhash",
                "addresses": ["1JqDybm2nWTENrHvMyafbSXXtTk5Uv5QAn"]
            }
        }, {
            "value": 44.44,
            "n": 1,
            "scriptPubKey": {
                "asm": "OP_DUP OP_HASH160 948c765a6914d43f2a7ac177da2c2f6b52de3d7c OP_EQUALVERIFY OP_CHECKSIG",
                "hex": "76a914948c765a6914d43f2a7ac177da2c2f6b52de3d7c88ac",
                "reqSigs": 1,
                "type": "pubkeyhash",
                "addresses": ["1EYTGtG4LnFfiMvjJdsU7GMGCQvsRSjYhx"]
            }
        }],
        "hex": "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"
    }, {
        "txid": "6359f0868171b1d194cbee1af2f16ea598ae8fad666d9b012c8ed2b79a236ec4",
        "hash": "6359f0868171b1d194cbee1af2f16ea598ae8fad666d9b012c8ed2b79a236ec4",
        "version": 1,
        "size": 257,
        "vsize": 257,
        "weight": 1028,
        "locktime": 0,
        "vin": [{
            "txid": "cf4e2978d0611ce46592e02d7e7daf8627a316ab69759a9f3df109a7f2bf3ec3",
            "vout": 1,
            "scriptSig": {
                "asm": "30440220032d30df5ee6f57fa46cddb5eb8d0d9fe8de6b342d27942ae90a3231e0ba333e02203deee8060fdc70230a7f5b4ad7d7bc3e628cbe219a886b84269eaeb81e26b4fe[ALL] 04ae31c31bf91278d99b8377a35bbce5b27d9fff15456839e919453fc7b3f721f0ba403ff96c9deeb680e5fd341c0fc3a7b90da4631ee39560639db462e9cb850f",
                "hex": "4730440220032d30df5ee6f57fa46cddb5eb8d0d9fe8de6b342d27942ae90a3231e0ba333e02203deee8060fdc70230a7f5b4ad7d7bc3e628cbe219a886b84269eaeb81e26b4fe014104ae31c31bf91278d99b8377a35bbce5b27d9fff15456839e919453fc7b3f721f0ba403ff96c9deeb680e5fd341c0fc3a7b90da4631ee39560639db462e9cb850f"
            },
            "sequence": 4294967295
        }],
        "vout": [{
            "value": 0.01,
            "n": 0,
            "scriptPubKey": {
                "asm": "OP_DUP OP_HASH160 b0dcbf97eabf4404e31d952477ce822dadbe7e10 OP_EQUALVERIFY OP_CHECKSIG",
                "hex": "76a914b0dcbf97eabf4404e31d952477ce822dadbe7e1088ac",
                "reqSigs": 1,
                "type": "pubkeyhash",
                "addresses": ["1H8ANdafjpqYntniT3Ddxh4xPBMCSz33pj"]
            }
        }, {
            "value": 2.99,
            "n": 1,
            "scriptPubKey": {
                "asm": "OP_DUP OP_HASH160 6b1281eec25ab4e1e0793ff4e08ab1abb3409cd9 OP_EQUALVERIFY OP_CHECKSIG",
                "hex": "76a9146b1281eec25ab4e1e0793ff4e08ab1abb3409cd988ac",
                "reqSigs": 1,
                "type": "pubkeyhash",
                "addresses": ["1Am9UTGfdnxabvcywYG2hvzr6qK8T3oUZT"]
            }
        }],
        "hex": "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"
    }, {
        "txid": "e9a66845e05d5abc0ad04ec80f774a7e585c6e8db975962d069a522137b80c1d",
        "hash": "e9a66845e05d5abc0ad04ec80f774a7e585c6e8db975962d069a522137b80c1d",
        "version": 1,
        "size": 225,
        "vsize": 225,
        "weight": 900,
        "locktime": 0,
        "vin": [{
            "txid": "f4515fed3dc4a19b90a317b9840c243bac26114cf637522373a7d486b372600b",
            "vout": 0,
            "scriptSig": {
                "asm": "3046022100bb1ad26df930a51cce110cf44f7a48c3c561fd977500b1ae5d6b6fd13d0b3f4a022100c5b42951acedff14abba2736fd574bdb465f3e6f8da12e2c5303954aca7f78f3[ALL] 04a7135bfe824c97ecc01ec7d7e336185c81e2aa2c41ab175407c09484ce9694b44953fcb751206564a9c24dd094d42fdbfdd5aad3e063ce6af4cfaaea4ea14fbb",
                "hex": "493046022100bb1ad26df930a51cce110cf44f7a48c3c561fd977500b1ae5d6b6fd13d0b3f4a022100c5b42951acedff14abba2736fd574bdb465f3e6f8da12e2c5303954aca7f78f3014104a7135bfe824c97ecc01ec7d7e336185c81e2aa2c41ab175407c09484ce9694b44953fcb751206564a9c24dd094d42fdbfdd5aad3e063ce6af4cfaaea4ea14fbb"
            },
            "sequence": 4294967295
        }],
        "vout": [{
            "value": 0.01,
            "n": 0,
            "scriptPubKey": {
                "asm": "OP_DUP OP_HASH160 39aa3d569e06a1d7926dc4be1193c99bf2eb9ee0 OP_EQUALVERIFY OP_CHECKSIG",
                "hex": "76a91439aa3d569e06a1d7926dc4be1193c99bf2eb9ee088ac",
                "reqSigs": 1,
                "type": "pubkeyhash",
                "addresses": ["16FuTPaeRSPVxxCnwQmdyx2PQWxX6HWzhQ"]
            }
        }],
        "hex": "01000000010b6072b386d4a773235237f64c1126ac3b240c84b917a3909ba1c43ded5f51f4000000008c493046022100bb1ad26df930a51cce110cf44f7a48c3c561fd977500b1ae5d6b6fd13d0b3f4a022100c5b42951acedff14abba2736fd574bdb465f3e6f8da12e2c5303954aca7f78f3014104a7135bfe824c97ecc01ec7d7e336185c81e2aa2c41ab175407c09484ce9694b44953fcb751206564a9c24dd094d42fdbfdd5aad3e063ce6af4cfaaea4ea14fbbffffffff0140420f00000000001976a91439aa3d569e06a1d7926dc4be1193c99bf2eb9ee088ac00000000"
    }],
    "time": 1293623863,
    "mediantime": 1293622620,
    "nonce": 274148111,
    "bits": "1b04864c",
    "difficulty": 14484.1623612254,
    "chainwork": "0000000000000000000000000000000000000000000000000644cb7f5234089e",
    "nTx": 4,
    "previousblockhash": "000000000002d01c1fccc21636b607dfd930d31d01c3a62104612a1719011250",
    "nextblockhash": "00000000000080b66c911bd5ba14a74260057311eaeb1982802f7010f1a9f090"
}

```

I read some articles about the structure and fields of bitcoin block data, but I can't find documents to explain every fields clearly and in detail.

Anyone can give me some detailed information about the fields, or recommend some articles or books?

**Tags:** block


---

## 1 answers

### Answer by username_1 on 2018-12-14. Score: 3

# What's in a Block?

A block is a data structure that contains transactions as well as metadata about the block. All transactions must be included in a valid block in order to be considered final. All full nodes on the network will store a copy of the block in order to validate new transactions and share the data with other nodes.

## Block Structure

```
$ bitcoin-cli -regtest getblockhash 0
0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206

$ bitcoin-cli -regtest getblock 0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206 0

```

`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`

This is the genesis block for the regtest network. It is hard coded in Bitcoin core and is the first block, so it does not reference any previous blocks. It also contains a message from Satoshi Nakamoto, the pseudonymous creator of Bitcoin in the coinbase scriptSig.

{block header} {transaction counter} {transactions}

### Block Header

{version 4B} {previous block hash 32B} {merkle root hash 32B} {time 4B} {bits 4B} {nonce 4B}

* Version (4 Bytes) - Block format version.
* Previous Block Hash (32 Bytes) - The hash of the preceding block. This is important to include in the header because the hash of the block is calculated from the header, and thus depends on the value of the previous block, linking each new block to the last. This is the link in the chain of the blockchain.
* Merkle Root Hash (32 Bytes) - The hash of the merkle tree root of all transactions in the block. If any transaction is changed, removed, or reordered, it will change the merkle root hash. This is what locks all of the transactions in the block.
* Time (4 Bytes) - Timestamp in Unix Time {TODO: provide link} (seconds). Since the clocks of each node around the world is not guaranteed to be synchronized, this is just required to be within {TODO} of the rest of the network.
* Bits (4 Bytes) - Target hash value in [Compact Format](https://bitcoin.org/en/developer-reference#target-nbits). The block hash must be equal to or less than this value in order to be considered valid.
* Nonce (4 Bytes) - Can be any 4 Byte value, and is continuously changed while mining until a valid block hash is found.

`01000000 0000000000000000000000000000000000000000000000000000000000000000 3ba3edfd7a7b12b27ac72c3e67768f617fc81bc3888a51323a9fb8aa4b1e5e4a dae5494d ffff7f20 02000000`

**Block Header:**

* Version - `01000000` (1)
* Previous Block Hash - `0000000000000000000000000000000000000000000000000000000000000000`
* Merkle Root Hash - `3ba3edfd7a7b12b27ac72c3e67768f617fc81bc3888a51323a9fb8aa4b1e5e4a`
* Time - `dae5494d` (1296688602 Wednesday, February 2, 2011 11:16:42 PM GMT)
* Bits - `ffff7f20` (`7fffff0000000000000000000000000000000000000000000000000000000000`)
* Nonce - `02000000` (2)

**Note:** Remember Bitcoin uses little endian format, which may seem backwards. You can use the provided tool `$ reverse_endian {hex}` to reverse the endianess of a hex string.

### Transaction Counter

`01` (1) Transaction in the block

* Transaction Counter (Variable Length) - Number of transactions in the block represented as a [Variable Length Integer](https://en.bitcoin.it/wiki/Protocol_documentation#Variable_length_integer).

### Transactions

See <https://en.bitcoin.it/wiki/Transaction>

**See also:**

* <https://en.bitcoin.it/wiki/Block>
* <https://en.bitcoin.it/wiki/Block_hashing_algorithm>

> **Comments:**
> **username_0**: thanks so much,  I will you read more documents from your recommended links  

---

