Edited ch09.asciidoc with Atlas code editor

ch09.asciidoc

@@ -15,7 +15,7 @@ One way to think about the blockchain is like layers in a geological formation,
 
 === Structure of a Block
 
-A block is a container data structure that aggregates transactions for inclusion in the public ledger, the blockchain. The block is made of a header, containing metadata, followed by a long list of transactions that make up the bulk of its size. The block header is 80 bytes, whereas the average transaction is at least 250 bytes and the average block contains more than 500 transactions. A complete block, with all transactions, is therefore 1,000 times larger than the block header. <<block_structure1>> describes the structure of a block.
+((("blocks", "structure of")))((("blockchain technology", "block structure")))A block is a container data structure that aggregates transactions for inclusion in the public ledger, the blockchain. The block is made of a header, containing metadata, followed by a long list of transactions that make up the bulk of its size. The block header is 80 bytes, whereas the average transaction is at least 250 bytes and the average block contains more than 500 transactions. A complete block, with all transactions, is therefore 1,000 times larger than the block header. <<block_structure1>> describes the structure of a block.
 
 [[block_structure1]]
 .The structure of a block
@@ -31,7 +31,7 @@ A block is a container data structure that aggregates transactions for inclusion
 [[block_header]]
 === Block Header
 
-The block header consists of three sets of block metadata. First, there is a reference to a previous block hash, which connects this block to the previous block in the blockchain. The second set of metadata, namely the _difficulty_, _timestamp_, and _nonce_, relate to the mining competition, as detailed in <<bitcoin_network_ch08>>. The third piece of metadata is the merkle tree root, a data structure used to efficiently summarize all the transactions in the block. <<block_header_structure_ch09>> describes the structure of a block header.
+((("blocks", "headers")))((("blockchain technology", "block headers")))The block header consists of three sets of block metadata. First, there is a reference to a previous block hash, which connects this block to the previous block in the blockchain. The second set of metadata, namely the _difficulty_, _timestamp_, and _nonce_, relate to the mining competition, as detailed in <<bitcoin_network_ch08>>. The third piece of metadata is the merkle tree root, a data structure used to efficiently summarize all the transactions in the block. <<block_header_structure_ch09>> describes the structure of a block header.
 
 
 [[block_header_structure_ch09]]