diff --git a/ch02.asciidoc b/ch02.asciidoc index d30b6bdf..00dcc882 100644 --- a/ch02.asciidoc +++ b/ch02.asciidoc @@ -69,14 +69,14 @@ Alice, introduced in the previous chapter, is a new user who has just acquired her first bitcoins. In <>, Alice met with her friend Joe to exchange some cash for bitcoins. Since then, Alice has bought additional bitcoins. Now Alice will make -her first retail transaction, buying a laptop from Bob's online store. +her first retail transaction, buying access to a premium podcast episode from Bob's online store. Bob's web store recently started accepting bitcoin payments by adding a bitcoin option to its website. The prices at Bob's store are listed in the local currency (US dollars), but at checkout, customers have the option of paying in either dollars or bitcoin. -Alice shops for a laptop and proceeds to the checkout page. At checkout, +Alice finds the podcast episode she wants to buy and proceeds to the checkout page. At checkout, Alice is offered the option to pay with bitcoin, in addition to the usual options. The checkout cart displays the price in US dollars and also in bitcoin (BTC), at Bitcoin's prevailing exchange rate. @@ -199,12 +199,12 @@ previous transaction's output as its input. In the previous chapter, Alice received bitcoin from her friend Joe in return for cash. That transaction created a bitcoin value locked by Alice's key. Her new transaction to Bob's Store references the previous transaction as an -input and creates new outputs to pay for the laptop and receive change. +input and creates new outputs to pay for the podcast and receive change. The transactions form a chain, where the inputs from the latest transaction correspond to outputs from previous transactions. Alice's key provides the signature that unlocks those previous transaction outputs, thereby proving to the Bitcoin network that she owns the funds. -She attaches the payment for the laptop to Bob's address, thereby +She attaches the payment for the podcast to Bob's address, thereby "encumbering" that output with the requirement that Bob produces a signature in order to spend that amount. This represents a transfer of value between Alice and Bob. This chain of transactions, from Joe to @@ -370,10 +370,10 @@ View the http://bit.ly/1tAeeGr[transaction from Joe to Alice]. ==== As you can see, Alice's wallet contains enough bitcoin in a single -unspent output to pay for the laptop. Had this not been the case, +unspent output to pay for the podcast. Had this not been the case, Alice's wallet application might have to "rummage" through a pile of smaller unspent outputs, like picking coins from a purse until it could -find enough to pay for the laptop. In both cases, there might be a need +find enough to pay for the podcast. In both cases, there might be a need to get some change back, which we will see in the next section, as the wallet application creates the transaction outputs (payments). @@ -393,7 +393,7 @@ for a signature from Bob. This transaction will also include a second output, because Alice's funds are in the form of a 0.10 BTC output, too much money for the 0.015 -BTC cup of laptop. Alice will need 0.085 BTC in change. Alice's change +BTC podcast. Alice will need 0.085 BTC in change. Alice's change payment is created by Alice's wallet as an output in the very same transaction as the payment to Bob. Essentially, Alice's wallet breaks her funds into two payments: one to Bob and one back to herself. She can @@ -670,7 +670,7 @@ thus providing assurance that the miners accepted it as valid. Bob can now spend the output from this and other transactions. For example, Bob can pay a contractor or supplier by transferring value from -Alice's laptop payment to these new owners. Most likely, Bob's bitcoin +Alice's podcast payment to these new owners. Most likely, Bob's bitcoin software will aggregate many small payments into a larger payment, perhaps concentrating all the day's bitcoin revenue into a single transaction. This would aggregate the various payments into a single