Fixes #410

01_introduction.asciidoc

@@ -94,7 +94,16 @@ The Lightning Network is a network that operates as a "second layer" protocol on
 [[user-stories]]
 === Lightning Network Use Cases, Users, and Their Stories
 
-As an electronic cash system, Bitcoin preserves the three most important properties of money (medium of exchange, store of value, and unit of account). Other relevant properties of digital payment systems include the ability of third parties to use them as a method of control and/or a tool of surveillance.
+Any system of money must exhibit, to some degree, the three fundamental properties:
+
+* Store of Value (SoV) - money must be useful as a store of value over time.
+* Medium of Exchange (MoE) - money can be exchanged for goods and services
+* Unit of Account (UoA) - money is used as a metric unit for measuring the value of things.
+
+Bitcoin is an electronic cash system that exhibits these properties to varying degrees. It has proven to be useful as a store of value and is used as a medium of exchange. Within the cryptocurrency economy, it is sometimes used as a unit of account to measure the exchange rate of other crypto-currencies.
+
+Other relevant properties of digital payment systems include the ability of third parties to use them as a method of control and/or a tool of surveillance.
+
 The invention of money (and in particular Bitcoin) was primarily made to facilitate trade and enable the exchange of value between people. However, without the Lightning Network (or another second layer or scaling solution), it would be infeasible for millions of people to concurrently use Bitcoin as a medium of exchange because the network itself would become overloaded, slow, and costly.
 
 To date, Bitcoin is the longest running, most secure cryptocurrency or electronic cash system and many people believe it represents the most stable store of value of all of the current cryptocurrencies. The Lightning Network allows people to send and receive bitcoin, without the overhead associated with on-chain transactions. This might seem confusing at first. You might be wondering how can the Lightning Network actually achieve this? While we could explain the network in computer science terms, it will be much easier to understand if we examine it from the perspective of people using it. In our examples, some of the people have already used Bitcoin and others are completely new to the Bitcoin network. Each of the people and their stories, as listed here, illustrates one or more specific use cases. We'll be revisiting them throughout this book: