Purpose The purpose of this book is to explain to information technology (IT) decision makers those aspects of finance that most affect their work. Most IT decision makers belong in one of two categories. Some know a lot about IT, but less about finance; the others know a lot about finance, but less about IT. In my experience, those in the first category often have to make financial decisions. Those in the second also, of course, have to make financial decisions, but about things whose characteristics stretch the normal financial and accounting rules up to, and sometimes beyond, their elastic limit. Among the characteristics of IT that provide interesting challenges for financial people are the following: • The accelerating rate of change • The short and unpredictable useful life of IT assets • The mixture of hardware, software and services • Upgradability • Networks that cross country boundaries • IT jargon Asked what characteristics of finance provide interesting challenges for IT people, many of them would answer - "Everything". However, items in the following selection are often particular causes of wonder: • Leasing • Why financial models always shrink benefits but never costs • Being told that a company with a mountain of profit is about to fail through lack of cash • Discovering that their budget has been charged with £113 485.