EECS Ch. 3

Database Software

Also called database manager or database management system (DBMS); application software that sets up and controls the structure of a database and access to the data. Important because: database software allows users to organize and manage huge amounts of data.

Key

Also called key field, primary key, sort key, index, or key-word; field used to sort data in a database. For example, if users sort records by age, then the age field is a key.

Macro

Also called keyboard shortcut; a single keystroke or command-or a series of keystrokes or commands-used to automatically issue a longer, predetermined series of keystrokes or commands.

Utility Programs

Also known as service programs; system software components that perform tasks related to the control, allocation, and maintenance of computer resources. Important because: utility programs enhance existing functions or provide services not supplied by other system software programs. Most computers come with built-in utilities as part of the system software; they usually include backup, data recovery, virus protection, data compression, and file defragmentation, along with check (scan) disk and disk cleanup.

Database

Collection of interrelated files in a computer system. These computer-based files are organized according to their common elements, so that they can be retrieved easily. Important because: business and organizations build databases to help them keep track of and manage their affairs. In addition, online database services put enormous resources at the user's disposal.

Software License

Contract by which users agree not to make copies of software to give away or resell. Important because: software manufacturers don't sell people software; they sell them licenses to become authorized users of the software.

Freeware

Copyrighted software that is distributed free of charge, today most often over the Internet. Saves users money.

Multitasking

Feature of OS software that allows the execution of two or more programs concurrently by one user almost at the same time on the same computer with one or two CPUs. For instance, you might write a report on your computer with one program while another plays a music CD.

Portable Document Format (PDF)

File format developed by Adobe Systems. PDF captures text, graphic, and formatting information from a variety of applications on different platforms making it possible to send documents and have them appear on the recipient's monitor (or printer) as they were intended to be viewed. Important because: a properly prepared PDF file maintains the original fonts, images, colors, and graphics, as well as the exact layout of the file.

Program Files

Files containing software instructions.

Data Files

Files that contain data - words, numbers, pictures, sounds, and so on. Important because: unlike program files, data files don't instruct the computer to do anything. Rather, data files are there to be acted on by program files.

Linux

Free (open-source) version of Unix OS, supported by the efforts of thousands of volunteer programmers. Important because: Linux is an inexpensive, open-source operating system useful for online applications and to PC users who have to maintain a web server or a network server.

Importing

Getting data from another source and then converting it into a format compatible with the program in which the user is currently working.

Booting

Loading an operating system into a computer's main memory. Important because: without booting, computers could not operate. The programs responsible for booting are stored permanently in the computer's electronic circuitry. When you turn on the machine, programs called diagnostic routines test the main memory, the central processing unit, and other parts of the system to make sure they are running properly. Next, BIOS (basic input/output system) programs are copied to main memory and help the computer interpret keyboard characters or transmit characters to the display screen or to a diskette. Then the boot program obtains the operating system, usually from the hard disk, and loads it into the computer's main memory, where it remains until you turn the computer off.

Operating System (OS)

Low-level master system of programs that manage the basic operations of the computer. Important because: these programs provide resource management services of many kinds. In particular, they handle the control and use of hardware resources, including disk space, memory, CPU time allocation, and peripheral devices. The operating system allows users to concentrate on their own tasks or applications rather than on the complexities of managing the computer.

Compression

Method of removing repetitive elements from a file so that the file requires less storage space, then later decrompressing the removed data, or restoring the repeated patterns. Important because: compression/decompression makes storage and transmission of large files, such as multimedia files, more feasible.

Unix

Proprietary multitasking operating system for multiple users that has built-in networking capability and versions that can run on all kinds of computers.

Open-Source Software

Software that any programmer can download from the Internet free and modify with suggested improvements. The only qualification is that changes can't be copyrighted; they must be made available to all and remain in the public domain. Important because: because this software is not proprietary, any programmer can make improvements, which can result in better quality software.

Application Software

Software that has been developed to solve a particular problem for users - to perform useful work on specific tasks or to provide entertainment. Important because: application software consists of most of the software you are familiar with and use on a daily basis.

Device Drivers

Specialized software programs - usually components of system software - that allow input and output devices to communicate with the rest of the computer system. Important because: Drivers are needed so that the computer's operating system can recognize and run peripheral hardware.

Supervisor or Kernel

The central component of the operating system that manages the CPU. The supervisor remains in main memory while the computer is running. as well as managing the CPU, it copies other nonresident programs into memory to perform tasks that support application programs.

System Software

The software that helps the computer perform essential operating tasks and enables the application software to run. The most important component of system software is the operating system, the master control program that runs the computer.

Graphical User Interface (GUI)

User interface in which icons and commands from menus may be selected by means of a mouse or keystrokes. Important because: GUIs are easier to use than command-driven interfaces.

User Interface

User-controllable graphic display screen that allows the user to communicate, or interact, with his or her computer. Important because: the interface determines the ease of use of hardware and software. The three types of user interface are command-driven, menu-driven, and graphical (GUI), which is now the most common. Without user interfaces, no one could operate a computer system.