K201 Exam 2
Terms
undefined, object
copy deck
- access time/speed
- measures amount of time required by the storage device to retrieve data and programs
- analog signal
- represents a range of frequencies, such as human voice, continuous wave signal, requires modem, cable, and telephone wall jack to convert to digital
- digital signal
- computers only understand this, conversion must occur, signal is either on or off
- ASCII
- american standard code for information interchange, binary coding scheme widely used on all computers, including microcomputers, eight bits per byte, one byte is one character
- backup
- windows utility program, protects from the effects of a disk failure by making a copy of selected or all files that have been saved onto a disk
- bar code reader
- photoelectric scanner that reads bar codes for processing
- batch processing
- performed all at once on data that has been collected over time
- real time processing
- also online processing, data is processed at the same time a transaction occurs
- biometrics/ biometric scanning
- devices that check fingerprints or retinal scans
- bit/ binary/ binary digit
- each one or zero is a bit
- bluetooth
- recent wireless technology that allows nearby devices to communicate without the connection of cables or telephone systems
- bus line
- electronic data roadway, along which bits travel, connects the parts of the cpu to each other and links the cpu with other important hardware, common connecting cable is bus network
- byte
- unit consisting of eight bits, 256 possible bit combinations in a byte, each byte represents one character
- cache memory
- area of random access memory (ram) set aside to store the most frequently accessed information, improves processing by acting as a temporary high-speed holding area between memory and the cpu allowing computer to detect which information in ram is most frequently used
- capacity
- how much data a particular storage medium can hold and another characteristic of secondary storage
- carpal tunnel syndrome
- disorder found among frequent computer users, consisting of damage to nerves and tendons in the hands
- coaxial cable
- high frequency transmission cable that replaces the multiple wires of telephone lines with a single solid copper core. it is used to deliver television signals as well as to connect computers in a network
- combination key
- keys such as the ctrl key that perform an action when held down in combination with another key
- cookies
- programs that record information on web site visitors
- data redundancy
- a common database problem in which data is duplicated and stored in different files
- denial of service attack
- dos, a variant virus in which web sites are overwhelmed with data and users are unable to access the web site, unlike a worm that self replicates a dos attack floods a computer or network with requests for information and data
- device driver
- special program associated with every device that allows communication between the operating system and the device
- direct access
- a fast approach to external storage, provided by disks, where information is not in a set sequence
- sequential access
- an approach to external storage, provided by magnetic tape, where information is stored in sequence
- dsl
- digital subscriber line, provides high speed connection using existing telephone lines
- ebcdic
- extended binary coded decimal interchange code, binary coding scheme that is a standard for minicomputers and mainframe computers
- encryption/ encrypting
- coding information so that only the user can read or otherwise use it
- ergonomics
- study of human factors related to things people use, concerned with fitting the job to the worker rather than forcing the worker to contort to fit the job
- extranet
- private network that connects more than one organization
- fiber optics/ fiber optic cable
- special transmission cable made of glass tubes that are immune to electronic interference, data is transmitted through fiber optic cables in the form of pulses of light
- field
- each column of information within a record is called a field. a field contains related information on a specific item like employee names within a company department
- file compression
- process of reducing the storage requirements for a file
- file decompression
- process of expanding a compressed file
- firewall
- security hardware and software, all communications into and out of an organization pass through a special security computer, called a proxy server, to protect all systems against external threats
- flash memory
- ram chips that retain data even when power is disrupted, flash memory is an example of solid state storage and is typically used to store digitized images and record mp3 files
- flexible keyboard
- fold or roll up for easy packing or storage, designed for mobile users who want a full size keyboard
- form
- electronic forms reflecting the contents of one record of table, primarily used to enter new records or make changes to existing records
- gps
- global positioning system, devices use location information to determine the geographic location of your car, for example
- head crash
- when a read-write head makes contact with the hard disks surface or particles on its surface, the disk surface becomes scratched and some or all data is destroyed
- infrared
- uses infrared light waves to communicate over short distances, sometimes referred to as line of sight communication because light waves can only travel in a straight line
- input device
- piece of equipment that translates data into a form a computer can process, examples are mouse and keyboard
- internal hard disk
- storage device consisting of one or more metallic platters sealed inside a container, internal hard disks are installed inside the system cabinet of a microcomputer, it stores the operating system and major applications like word
- external hard disk/drive
- uses the same technology as an internal hard disk but is used primarily to complement an internal hard disk by providing additional storage, they are typically connected to a usb or firewire port on the system unit and are easily removed
- internet scam
- a fraudulent act or operation designed to trick individuals into spending their time and money for little or no return
- intranet
- like the internet, it typically provides email, mailing lists, newsgroups, and ftp services, but it is accessible only to those within the organization, organization use intranets to provide information to their employees
- lan
- local area network, network consisting of computers and other devices that are physically near each other, such as withing the same building
- light pen
- a light sensitive penlike device, placing the pen against the monitor closes a photoelectric circuit and identifies the spot for entering or modifying data
- man
- metropolitan area network, link between office buildings in a city
- modem
- short for modulator demodulator, it is a communication device that translates the electronic signals from a computer into electronic signals that can travel over telephone lines
- nic
- network interface card, network adapter card, used to connect to a computer to one or more computers forming a communication network whereby users can share data, programs, and hardware
- node
- any device connected to a network, for example, a node is a computer, printer, or data storage device and each device has its own address on the network, also within hierarchical databases, fields or records are structured in nodes
- ocr
- optical character recognition, scanning device that uses special preprinted characters, such as those printed on utility bills that can be read by a light source and changed into machine readable code
- omr
- optical mark recognition, device that senses the presence or absence of a mark, such as a pencil mark, example, an omr device is used to score multiple choice tests
- optical mouse
- a type of mouse that emits and senses light to detect mouse movements
- output devices
- equipment that translates processed information from the central processing unit into a form that can be understood by humans, the most common output devices are monitors and printers
- peer to peer network
- p2p, nodes can act as both servers and clients, for example, on microcomputer can obtain files located on another microcomputer and also can provide files to other microcomputers
- port
- connecting socket on the outside of the system unit, used to connect input and output devices to the system unit
- protocol
- rules for exchanging data between computers, http:// is most common
- query
- a question or request for specific data contained in a database, used to analyze data
- record
- each row of information in a database, each row contains fields of data about some specific item, like employee name, address, phone, and so forth. a record represents a collection of attributes describing an entity
- report
- can be lists of fields in a table or selected fields based on a query, typical database reports include sales summaries, phone lists, and mailing labels
- ring/ ring network
- network in which each device is connected to two other devices, forming a ring. there is no host computer, and messages are passed around the ring until they reach the correct destination
- server
- a host computer with a connection to the internet that stores document files used to display web pages. depending on the resources shared, it may be called a file server, printer server, communication server, web server, or database server
- smart card
- card about the size of a credit card containing a tiny built in microprocessor. it can be used to hold such information as personal identification, medical and financial knowledge, and credit card numbers. information on this card is protected by a password, which offers security and privacy
- solid state storage
- a secondary storage device that has no moving parts. data is stored and retrieved electronically directly from these devices, much as they would be from conventional computer memory
- star/ star network
- network of computers or peripheral devices linked to a central computer through which all communications pass. control is maintained by polling. the configuration of the computers looks like a star surrounding and connected to the central computer in the middle
- storage devices
- hardware that reads data and programs from storage media. most also write to storage media
- surge protector
- device separating the computer from the power source of the wall outlet, when a voltage surge occurs, a circuit breaker is activated, protecting the computer system
- system unit
- part of a microcomputer that contains the cpu, also known as the system cabinet or chassis, it is the container that houses most of the electronic components that make up the computer system
- table
- list of records in a database, tables make up the basic structure of a database. their columns display field data and their rows display records.
- tcp/ip
- transmission control protocol/internet protocol, the standard protocol for the internet, the essential features of this protocol involve 1. identifying sending and receiving devices and 2. reformatting information for transmission across the internet
- telephony
- communication that uses the internet rather than traditional communication lines to connect two or more people via telephone
- toggle key
- turn a feature on or off like the caps lock key
- trojan horse
- program that is not a virus but is a carrier of viruses. the most common trojan horses appear as free computer games, screen savers, or antivirus programs. once downloaded they locate and disable existing virus protection and then deposit the virus
- twisted pair [cable]
- pairs of copper wire that are twisted together
- unicode
- a 16 bit code designed to support international languages, like chinese or japanese
- virus
- hidden instructions that migrate through networks and operating systems and become embedded in different programs. they may be designed to destroy data or simply to display messages
- wan
- wide area network, countryside and worldwide networks that use microwave relays and satellites to reach users over long distances
- wifi
- wireless fidelity, wireless standard also known as 802.11, used to connect computers to each other and to the internet
- wireless keyboard
- transmits input to the system through the air, providing greater flexibility and convenience
- anti virus program
- a utility program that guards a computer system from viruses or other damaging programs
- blu ray disc
- high definition disc, blue colored laser reads disc, capacity of 25 to 50 gigabytes, requires special drive, comes in read only, write once, rewritable
- data flow diagrams
- show data or information flow within an information system, date is traced from its origin through processing, storage, and output
- types of databases
- individual (microcomputer), company, distributed, commercial
- dpi
- dots per inch, way that printer resolution is measured
- ppm
- pages per minute, way that printer speed is measured
- malware
- malicious software, designed to damage or disrupt a computer system. examples, viruses, worms, trojan horses
- examples of standard ports
- serial, parallel, universal serial bus, firewire, ethernet
- examples of specialized ports
- sony/phillips digital interconnect format, high definition multimedia interface, musical intrument digital interface, infrared data association
- voltage surge/ electricity spike
- too much electricity, as when lightening or some other electrical disturbance affects the power line
- computer clock
- signal that oscillates between a high and low state and is utilized like a metronome to coordinate actions of circuits
- field size
- length of data record field for item number, etc that specifies the maximum allowable number of characters
- human error
- accidental deletion of single file to deletion of database or reformatting of a disk
- isdn
- integrated services digital network, set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the traditional circuits of the public switched telephone network
- physical transmission media
- what carries the communication signal from one system to another, examples are twisted pair cable, coaxial cable, and fiber optic cable
- quarantined file
- an undesirable file that has been infected by a virus or spyware to a folder that is not easily accessible
- qwerty
- most used keyboard layout
- importing
- to transfer data into a database
- exporting
- to transfer data out of a database
- examples of storage devices
- internal hard disk, external hard drive, pc card hard disk
- types of system unit
- desktop, notebook, tablet pc, handheld