Vocabulary
Directions: Scan the following passage and find the words which have roughly the same meanings as those given below. The number in the brackets after each word definition refers to the number of paragraph in which the target word is.  

     1. Communication networks are arrangements of hardware and software that allow users to exchange information. This very broad definition will help you begin learning about one of the fastest-growing areas in electrical engineering and computer science. Once we examine some common communication networks, we will develop a more precise definition. We will elaborate on the importance of this field.
     2. The telephone network is the most familiar and ubiquitous communication network. It is designed for voice transmission. An office computer network is a communication network used by organizations to connect personal computers and workstations so they may share programs and data and to link those computers to printers and, possibly, to some other peripherals (e.g., file servers that provide mass storage or plotters). Computer networks also are used in manufacturing plants to connect machine tools, robots, and sensors. The Internet is a network of computer networks that covers most of the world and allows millions of users to exchange messages and computer files and some limited video and audio signals.
     3. Although all these systems are communication networks, they are quite different in the information that they transmit and in the way they are used. Nevertheless, they operate on similar principles. The unifying characteristics of all networks help us develop a definition of communication networks that describes the arrangements of hardware and software that we study in this text. Each system described is designed to exchange information, which may be voice, sounds, graphics, pictures, video, text, or data, among users. Most often the users are humans, but they also can be computer programs or devices. Before the information is transmitted, it is converted into bits (zeros or ones). Then the bits are sent to a receiver as electrical or optical signals (electromagnetic waves, to be more precise). Finally, the information is reconstructed from the received bits. This transmission method, called digital transmission, reduced the transmission errors.