Edited ch02_overview.adoc with Atlas code editor

ch02_overview.adoc

@@ -47,7 +47,7 @@ example, we will provide a URL so you can look it up yourself and study
 it in detail.
 
 [[block-explorer-privacy]]
-.Block explorer privacy warning
+.Block Explorer Privacy Warning
 [WARNING]
 ====
 Searching information on a block explorer may disclose to its operator
@@ -80,17 +80,9 @@ usual options. The checkout cart displays the price in US dollars and
 also in bitcoin (BTC), at Bitcoin's prevailing exchange rate.
 
 Bob's
-e-commerce system will automatically create a QR code containing an
+ecommerce system will automatically create a QR code containing an
 _invoice_ (<<invoice-QR>>).
 
-Unlike a QR code that simply contains a destination Bitcoin address, this
-invoice is a QR-encoded URI that contains a destination address,
-a payment amount, and a description.
-This allows a Bitcoin wallet application to prefill the
-information used to send the payment while showing a human-readable
-description to the user. You can scan the QR code with a bitcoin wallet
-application to see what Alice would see.
-
 ////
 TODO: Replace QR code with test-BTC address
 ////
@@ -99,6 +91,15 @@ TODO: Replace QR code with test-BTC address
 .Invoice QR code
 image::images/mbc3_0202.png["payment-request"]
 
+Unlike a QR code that simply contains a destination Bitcoin address, this
+invoice is a QR-encoded URI that contains a destination address,
+a payment amount, and a description.
+This allows a Bitcoin wallet application to prefill the
+information used to send the payment while showing a human-readable
+description to the user. You can scan the QR code with a bitcoin wallet
+application to see what Alice would see:
+
+
 [TIP]
 ====
 Try to scan this with your wallet to see
@@ -139,7 +140,7 @@ millibitcoins and satoshis.
 ====
 
 You can examine Alice's transaction to Bob's Store on the blockchain
-using a block explorer site (<<view_alice_transaction>>):
+using a block explorer site (<<view_alice_transaction>>).
 
 [[view_alice_transaction]]
 .View Alice's transaction on https://blockstream.info/tx/674616f1fbc6cc748213648754724eebff0fc04506f2c81efb1349d1ebc8a2ef[Blockstream Explorer]
@@ -251,9 +252,8 @@ In addition to one or more outputs that pay the receiver of
 bitcoins, many transactions will also include an output that pays the
 spender of the bitcoins, called a _change_ output.
 This is because transaction inputs,
-like currency notes, cannot be partly spent. If you purchase a $5 US dollar
-item in a store but use a $20 dollar bill to pay for the item, you
-expect to receive $15 dollars in change. The same concept applies to
+like currency notes, cannot be partly spent. If you purchase a $5 US item in a store but use a $20 bill to pay for the item, you
+expect to receive $15 in change. The same concept applies to
 Bitcoin transaction inputs. If you purchased an item that costs 5
 bitcoins but only had an input worth 20 bitcoins to use, you would send one
 output of 5 bitcoins to the store owner and one output of 15 bitcoins back
@@ -266,7 +266,7 @@ payment output.
 Importantly, the change address does not have to be the
 same address as that of the input and for privacy reasons is often a new
 address from the owner's wallet.  In ideal circumstances, the two
-different uses of outputs both use never-before-been addresses and
+different uses of outputs both use never-before-seen addresses and
 otherwise look identical, preventing any third party from determining
 which outputs are change and which are payments.  However, for
 illustration purposes, we've added shading to the change outputs in
@@ -274,16 +274,16 @@ illustration purposes, we've added shading to the change outputs in
 
 Not every transaction has a change output.  Those that don't are called
 _changeless transactions_ and they can have only a single output.
-Changeless transaction are only a practical option if the amount being
+Changeless transactions are only a practical option if the amount being
 spent is roughly the same as the amount available in the transaction
 inputs minus the anticipated transaction fee.  In <<transaction-chain>>
 we see Bob creating Tx3 as a changeless transaction that spends the
 output he received in Tx2.
 
-==== Coin selection
+==== Coin Selection
 
 Different wallets use different strategies when choosing which
-inputs to use to a payment, called _coin selection_.
+inputs to se in a payment, called _coin selection_.
 
 They might aggregate many small
 inputs, or use one that is equal to or larger than the desired payment.
@@ -306,7 +306,7 @@ transaction has one input and two outputs and is shown in
 .Most common transaction
 image::images/mbc3_0205.png["Common Transaction"]
 
-Another common form of transaction is a _consolidation transaction_ that spends several inputs
+Another common form of transaction is a _consolidation transaction_, which spends several inputs
 into a single output (<<transaction-consolidating>>). This represents
 the real-world equivalent of exchanging a pile of coins and currency
 notes for a single larger note. Transactions like these are sometimes
@@ -317,7 +317,7 @@ generated by wallets and businesses to clean up lots of smaller amounts.
 image::images/mbc3_0206.png["Aggregating Transaction"]
 
 Finally, another transaction form that is seen often on the
-blockchain is _payment batching_ that pays to multiple outputs
+blockchain is _payment batching_, which pays to multiple outputs
 representing multiple recipients (<<transaction-distributing>>).
 This type of transaction is sometimes used by commercial entities to
 distribute funds, such as when processing payroll payments to multiple
@@ -424,7 +424,7 @@ the software logic and the data necessary for them to fully verify the
 correctness of a new transaction.  The connections between peers are
 often visualized as edges (lines) in a graph, with the peers themselves
 being the nodes (dots).  For that reason, Bitcoin peers are commonly
-called "full verification nodes", or _full nodes_ for short.
+called "full verification nodes," or _full nodes_ for short.
 
 Alice's wallet application can send the new
 transaction to any Bitcoin node over any type of
@@ -433,7 +433,7 @@ to another program (such as a block explorer) that will relay it to a
 node.  Her Bitcoin wallet does not have
 to be connected to Bob's Bitcoin wallet directly and she does not have
 to use the internet connection offered by Bob, though both those
-options are possible, too. Any Bitcoin node that receives a
+options are possible too. Any Bitcoin node that receives a
 valid transaction it has not seen before will forward it to
 all other nodes to which it is connected, a propagation technique known
 as _gossiping_. Thus, the transaction rapidly propagates out across the
@@ -483,19 +483,19 @@ Mining achieves a fine balance between cost and reward. Mining uses
 electricity to solve a computational problem. A successful miner will
 collect a _reward_ in the form of new bitcoins and transaction fees.
 However, the reward will only be collected if the miner has only
-included valid transactions, with the Bitcoin Protocol's rules for
+included valid transactions, with the Bitcoin protocol's rules for
 _consensus_ dermining what is valid.  This delicate balance provides
 security for Bitcoin without a central authority.
 
 Mining is designed to be a decentralized lottery.  Each miner can create
 their own lottery ticket by creating a _candidate block_ that includes
 the new transactions they want to mine plus some additional data fields.
-The miner inputs their candidate into a specially-designed algorithm that
+The miner inputs their candidate into a specially designed algorithm that
 scrambles (or "hashes") the data, producing output that looks nothing
 like the input data.  This _hash_ function will always produce the same
 output for the same input--but nobody can predict what the output will
 look like for a new input, even if it is only slighly different from a
-previous input.  If the output of hash function matches a template
+previous input.  If the output of the hash function matches a template
 determined by the Bitcoin protocol, the miner wins the lottery and
 Bitcoin users will accept the block with its transactions as a
 valid block.  If the output doesn't match the template, the miner makes
@@ -510,7 +510,7 @@ valid block something that requires an incredible amount of work to
 create but only a trivial amount of work to verify.  The simple
 verification process is able to probabalistically prove the work was
 done, so the data necessary to generate that proof--in this case, the
-block--is called Proof-of-Work (PoW).
+block--is called proof of ork (PoW).
 
 Transactions are added to the new block, prioritized by the highest fee rate
 transactions first and a few other criteria. Each miner starts the
@@ -518,13 +518,13 @@ process of mining a new candidate block of transactions as soon as they receive
 previous block from the network, knowing that some other miner won that
 iteration of the lottery.  They immediately create a new candidate block
 with a commitment to the previous block, fill it with transactions, and start
-calculating the Proof-of-Work for the candidate block. Each miner includes a
+calculating the PoW for the candidate block. Each miner includes a
 special transaction in their candidate blocks, one that pays their own Bitcoin address
 the block reward plus the sum of
 transaction fees from all the transactions included in the candidate block. If they
-finds a solution that makes the candidate into a valid block, they receives this reward
-after his successful block is added to the global blockchain and the
-reward transaction he included becomes spendable. Miners who participates in a mining pool have set up their
+find a solution that makes the candidate into a valid block, they receive this reward
+after their successful block is added to the global blockchain and the
+reward transaction they included becomes spendable. Miners who participate in a mining pool have set up their
 software to create candidate blocks that assign the reward to a pool address.
 From there, a share of the reward is distributed to members of the pool
 miners in proportion to the amount of work they contributed.
@@ -548,7 +548,7 @@ transaction that doesn't pay Bob) would require performing the same
 amount of work as it will take all Bitcoin miners to create an entirely
 new block.  When there are multiple alternative blocks to choose from,
 Bitcoin full nodes choose the chain of valid blocks with the most total
-Proof-of-Work, called the _best blockchain_.  For the entire network to
+PoW, called the _best blockchain_.  For the entire network to
 accept an alternative block, an additional new block would need to be
 mined on top of the alternative.
 
@@ -557,7 +557,7 @@ alternative to the transaction where she pays Bob, perhaps with
 Alice paying miners a share of the money she previously paid Bob.  This
 dishonest behavior will require they expend the effort required to
 create two new blocks.  Instead, miners who behave honestly can create a
-single new block and and receive all of the fees from the transactions
+single new block and receive all of the fees from the transactions
 they include in it, plus the block subsidy.  Normally, the high cost of
 dishonestly creating two blocks for a small additional payment is much
 less profitable than honestly creating a new block, making it unlikely
@@ -575,7 +575,7 @@ Approximately 19 minutes
 after the block containing Alice's transaction is broadcast, a new block
 is mined by another miner. Because this
 new block is built on top of the block that contained Alice's
-transaction (giving Alice's transaction two confirmations) Alice's
+transaction (giving Alice's transaction two confirmations), Alice's
 transaction can now only be changed if two alternative blocks are
 mined--plus a new block built on top of them--for a total of three
 blocks that would need to be mined for Alice to take back the money she
@@ -584,8 +584,7 @@ transaction counts as an additional confirmation.  As the blocks pile on
 top of each other, it becomes harder to reverse the transaction, thereby
 giving Bob more and more confidence that Alice's payment is secure.
 
-In <<block-alice1>>,  we can
-the block which contains Alice's transaction. Below it are
+In <<block-alice1>>,  we can see the block that contains Alice's transaction. Below it are
 hundreds of thousands of blocks, linked to each other in a chain of
 blocks (blockchain) all the way back to block #0, known as the _genesis
 block_. Over time, as the "height" of new blocks increases, so does the
@@ -633,4 +632,4 @@ from owner to owner. We also tracked Alice's transaction, from the
 moment it was created in her wallet, through the Bitcoin network and to
 the miners who recorded it on the blockchain. In the rest of this book,
 we will examine the specific technologies behind wallets, addresses,
-signatures, transactions, the network, and finally mining.
+signatures, transactions, the network, and finally, mining.