business activities involving the computer that generates the ones and zeroes. Those ones and zeroes are fed into another computer, where an application converts them into a spreadsheet of sales figures (information) for the store from which they originated. A financial analyst studies the spreadsheet, calculates a few ratios, examines some historical data (including not only sales numbers but demographics, weather patterns, and political trends), and makes an informed prediction about future stocking requirements and advertising focal points for the store based on the knowledge that the analyst was able to create from the distilled information. That's knowledge. To take it one step further, once decisions have been made and the results of those Superscript(1) realize that this term has fallen out of favor, but I use it here for historical accuracy. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. First Things First First Things First decisions have been seen, wisdom allows decision makers to learn from their decisions. So they can make them again if the results are positive, or choose differently if they're not. Data, information, knowledge, and wisdom-a critical continuum. Data communications relies on a carefully designed set of rules that governs the manner in which computers exchange data. These rules are called protocols, and they are centrally important to the study of data communications. Dictionaries define "protocol" as "a code of correct con- duct." From the perspective of data communications, they define it as "a standard procedure for regulating the transmission of data between com- puters," which is itself"a code of correct conduct." These protocols, which will be discussed in detail later in this book, provide a widely accepted methodology for everything from the pin assignments on physical con- nectors to the sublime encoding 