4b 4i computers

◾ Server: A computer dedicated to serving and supporting a network, a group of network users, and/or their information needs. Many networks employ servers to provide a centrally accessible storage space for data, and share common devices like printers and scanners. A small network server may look similar to a desktop PC, but may have a different operating system, such as Windows Server or Linux. A large server that manages a wide-ranging network may look similar to a mainframe. A group of servers located together in a single room or facility is called a server farm, or server cluster. Large Internet service provider (ISP) companies maintain extensive server farms.

◾ Mainframe: A large and powerful computer capable of processing and storing large amounts of business data. For example, a mainframe might collect all the sales data from hundreds of cash registers in a large department store and make it available to executives. The modern mainframe unit itself is a large cabinet, or a series of cabinets, each about the size of a refrigerator (see Figure 1.6). A mainframe may be stored in its own air-conditioned room in a business or school, and may have multiple employees monitoring and maintaining it. In earlier decades, smaller and less expensive multiuser computers called minicomputers were employed in many businesses, but minicomputers are no longer widely used.

◾ Supercomputer: A supercomputer is the largest and most powerful type of computer available, occupying large rooms and even entire floors of a building. Supercomputers are often employed in fields such as cryptanalysis (code breaking), molecular modeling, weather forecasting, and climate mapping. Supercomputers typically are used in high-tech academic, governmental, and scientific research facilities.