wiki commit

protocol/blockchain/block/block-header.md

@@ -7,7 +7,6 @@ With a block header, you can:
  1. Calculate the hash of the block.
 	 - The double SHA-256 hash of the block header.
  2. Confirm the [proof of work](/protocol/blockchain/proof-of-work) was executed correctly.
-	 - See [Difficulty Adjustment Algorithm](/protocol/blockchain/proof-of-work/difficulty-adjustment-algorithm) for more details.
  3. Determine the relative location of the block in the blockchain.
 	 - Using the previous block hash contained in the header
 
@@ -21,13 +20,13 @@ Since validation of all the transactions in the block can be expensive, the abil
 | previous block hash | 32 bytes | [block hash](/protocol/blockchain/hash)<sup>[(LE)](/protocol/misc/endian/little)</sup> | The hash of the block immediately preceding this block in the blockchain. |
 | merkle root | 32 bytes | [merkle root](/protocol/blockchain/merkle-tree)<sup>[(LE)](/protocol/misc/endian/little)</sup> | The merkle tree root of the transactions in the block. |
 | timestamp | 4 bytes | unix timestamp<sup>[(LE)](/protocol/misc/endian/little)</sup> | The epoch timestamp of the block in seconds. |
-| difficulty target | 4 bytes | [difficulty target](#difficulty-target-encoding)<sup>[(LE)](/protocol/misc/endian/little)</sup> | The difficulty that the block must achieve to be valid.  This value is determined by the timestamps of previously mined blocks. |
+| difficulty target | 4 bytes | [difficulty target](#difficulty-target-encoding)<sup>[(LE)](/protocol/misc/endian/little)</sup> | The difficulty that the block must achieve to be valid.  This value is determined by the timestamps of previously mined blocks.  See [Target Difficulty](/protocol/blockchain/proof-of-work#target-difficulty) for more information. |
 | nonce | 4 bytes | bytes<sup>[(LE)](/protocol/misc/endian/little)</sup> | A random value that is repeatedly changes during block mining in order to achieve the block hash requirements. |
 
 ### Difficulty Target Encoding
 
 Within the block header, the difficulty target uses a special floating-point representation that helps keep the size of the block header small.
-While the difficulty adjustment algorithm attempts to calculate the ideal target (i.e. the value the block hash must be "less than"), it undergoes a lossy conversion when put in the block header:
+While the [difficulty adjustment algorithm](/protocol/blockchain/proof-of-work/difficulty-adjustment-algorithm) attempts to calculate the ideal target (i.e. the value the block hash must be "less than"), it undergoes a lossy conversion when put in the block header:
 
 | Field | Length | Format | Description |
 |--|--|--|--|

protocol/blockchain/proof-of-work.md

@@ -16,7 +16,10 @@ This is only quasi-random because the likelihood of building a block with an app
 
 ## Target Difficulty
 
-
+As the network's hashing power changes, the proof-of-work algorithm adjusts to compensate.
+With a stated goal of averaging 10 minutes per block mined, the work required to successfully mine a block is periodically adjusted to match the actual rate at which blocks were mined over a given period of time.
+At any given point, the next block to be mined must hash to a value that, when interpreted as an integer, must be below a target value, called the difficulty, that is deterministically calculated using the difficulties and timestamps of prior blocks.
+See [Difficulty Adjustment Algorithm](/protocol/blockchain/proof-of-work/difficulty-adjustment-algorithm) for more details.
 
 ## Extra Nonce