TO THE READER
Computers are no longer just for specialists. Today, computing is not just a profession and a hobby; it is also a tool used in virtually all human activities.
That’s why we’ve compiled this book of background knowledge. Its pur-pose is to tell you the things other people think you already know.
We design this book to have a convenient size so it can be easily carried around. In compiling a book this size, we have had to be selective. The quickest way to identify a word that you can’t find in a book is probably to do a web search (see SEARCH ENGINE). Also, some terms are almost always abbreviated, and in that case you should look for the abbreviation rather than the full term.
Much has changed since the first edition of this book was published more than twenty years ago. New terms are being invented every day. We regularly update the book, and this edition contains new entries on a vari-ety of topics including Windows Vista and Mac OS X. We’ve also cut out material that was showing its age.
Terms are marked slang or humorous if they are seldom used in serious writing. They are marked as jargon if, in our estimation, they are somewhat pretentious new names for old concepts and are not likely to endure. We provide occasional Usage notes to explain grammar, spelling, and proper use of words, such as the exact difference between disc and disk.
Throughout, we use SMALL CAPITALS to mark important words that are defined elsewhere in this book. By following cross-references, you can quickly find many entries that pertain to whatever interests you. Here are some entries you may wish to start with to learn about particular topics:

• Internet culture: CHAT ROOM
• right and wrong: COMPUTER ETHICS
• safe computing: COMPUTER SECURITY
• solving exceptionally difficult problems: ARTIFICIAL INTELLIGENCE
• productively using computers in business and daily life: APPLICATION PROGRAM
• listening to music: DIGITAL MUSIC
• taking pictures: DIGITAL CAMERA
• creating web pages: HTML
• writing computer programs: PROGRAMMING LANGUAGE
• software that controls a computer: OPERATING SYSTEM
• how a computer works: COMPUTER ARCHITECTURE
• networking and the Internet: INTERNET
• connecting computers wirelessly: WIRELESS COMMUNICATION
• electronic components: TRANSISTOR