A group of characters (bytes) that identify a characteristic of an entity. A data value is a specific value found in a field. Fields can consist of a single character (Y, N) but usually consist of a group of characters. Each field is defined as a specific data type. Date, Text and Number are common data types.
Define "application software".
The diverse group of end-user programs that accomplish specific user objectives. Can be general purpose (word processors, spreadsheets, databases) or custom-developed for a specific application (ex.: a marketing information system for a clothing designer). May be purchased "off the shelf" or developed internally.
Define a "bit" (binary digit).
An individual zero or one; the smallest piece of information that can be represented.
A group of (usually) eight bits that are used to represent alphabetic and numeric characters and other symbols (3, g, X, ?, etc.). Several coding systems are used to assign specific bytes to characters. ASCII and EBCIDIC are the two most commonly used coding systems. Each system defines the sequence of zeros and ones that represent each character.
Define "operating system".
The interface between the user and the computer hardware.
Define "systems software".
The programs that run the computer and support system management operations.
A group of related fields (or attributes) that describe an individual instance of an entity (a specific invoice, a particular customer, an individual product).
A collection of records for one specific entity (an Invoice File, a Customer File, a Product File). In a relational database environment, files are also known as tables.
Define "programming languages".
All software is created using programming languages. They consist of sets of instructions and a syntax that determine how the instructions can be put together.
Computers at the leading edge of processing capacity. Their definition is constantly changing as the supercomputer of today often becomes the personal computer of tomorrow. They are generally used for calculation-intensive scientific applications, for example, weather forecasting and climate research.
What are input devices?
These devices instruct the CPU and supply data to be processed. For example: keyboard, mouse, trackball, touch-screen technology, point of sale (POS) scanners.
What are "microcomputers" or "personal computers (PCs)"?
These computers comprise an extremely diverse group of devices ranging from handheld personal digital assistants (PDAs) through desktop machines that can serve as components in large, networked environments. Some of the more common classifications include fat or thin clients and workstations. In addition, servers are computers that have been configured to provide resources to the network.
What are output devices?
These devices transfer data from the processing unit to other formats. For example: printers, plotters, monitors, flat panel displays, CRT (Cathode Ray Tube) displays.
What is the purpose of secondary storage devices?
Provide permanent storage for programs and data. Depending on the way the devices are set up, they can either be online (the data on the device is available for immediate access by the CPU) or offline (the device is stored in an area where the data is not accessible to the CPU).
What are magnetic disks?
These are random access devices. Data can be stored on, and retrieved from, the disk in any order. This is the most efficient way to store and retrieve individual records. Magnetic disks are the most commonly used form of secondary storage.
What is a magnetic tape?
This is a sequential access device. Data is stored in order of the primary record key (i.e. document number, customer number, inventory number, etc.) and must also be retrieved sequentially. Although once used for transaction processing, this medium is now used mostly for archiving data.
How is read-only memory (ROM) used?
Used to permanently store the data needed to power on the computer; includes portions of the operating system.
What are flash drives (also known as jump drives or thumb drives)?
These are very small, portable devices that can store anywhere from 500 M of data to over several gigabytes of data. The term "drive" is a bit of a misnomer as there are no moving parts to the "drive." Rather, the memory in a flash drive is similar to the RAM used as primary storage for your CPU.
Define "central processing unit (CPU)".
The CPU is the control center of the computer system. It has three principal components.
What is the purpose of the Arithmetic Logic Unit (ALU)?
To performs arithmetic calculations.
What is the purpose of primary storage (main memory)?
To store programs and data until they are ready to be used by the computer's processor. Primary storage is divided into two main parts - random access memory (RAM) and read-only memory (ROM).
Define "mainframe computers".
Computers used by commercial organizations to support mission critical tasks such as sales and order processing, inventory management, and e-commerce applications. Unlike supercomputers, which tend to support processor-intensive activities (i.e., a small number of highly complex calculations), mainframe computers tend to be input/output (I/O) intensive (i.e., a very large numbers of simple transactions). Mainframes frequently support thousands of users at a single point in time.
What does a control unit do?
Interprets program instructions.
What does random access memory (RAM) store?
It stores data temporarily while it is being processed.
What is an optical disk?
These use laser technology to "burn" data on the disk (although some rewritable disks use magnetic technology to record data). In general, read-only and write-once optical disks are a more stable storage medium than magnetic disks. Optical disks, like magnetic disks are random access devices. There are several different types of optical disks.
Devices that transfer data to or from the CPU but do not take part in processing data. Peripherals are commonly known as input and output devices (I/O devices).
What constitutes computer hardware?
This includes the physical equipment in your computer and the equipment that your computer uses to connect to other computers or computer networks. Computer hardware falls into four principal classifications.
Define "batch processing".
Periodic transaction processing method in which transactions are processed in groups.
What are "time lags"?
This is an inherent part of batch processing. There is always a time delay between the time the transaction occurs, the time that the transaction is recorded, and the time that the master file is updated.
Define "master files".
Computerized data files equivalent to the ledgers found in manual accounting system.