CTA 100 Final Ch 7-13

seconadarystorage

provides permanent or non volatile storage

media

physical material that holds the data and programs

capacity

measures how much a particular storage medium can hold

storage devices

hardware that reads data and programs from storage media ( moat write to storage media)

access speed

measures the amount of time required by the storage device to retrieve data and programs

RAID- redundant arrays of inexpensive disks

improve performance by expanding external storage, improving access speed, and providing reliable storage ( several are connected to one another)

optical disc

can hold over 128gb of data

lands

the 1s and 0s are represented by flat areas

pits

bumpy areas

optical disc drive

a laser that projects a tiny beam of light on these areas

compact discs (CD)

the first widely available optical format for PC users, store 700 MB of storage

digital versatile discs (DVD)

the standard for PCs; store 4.7 GB

blue ray discs (BD)

newest form; designs to store high def. video

read-only (ROM) discs

cannot be written on or erased by the user

write-once discs

can be written on once; after that the disc can be read many times but cannot be written or erased

re writable discs

disc surface is not permanently altered when data is recorded

twisted- pair cable

consists of copper wire that is twisted together ; standard telephone lines and Ethernet cables

coaxial cable

high frequency transmission cable, replaces the multiple wires of telephone lines; used to deliver tv signals as well as to connect to computers in a network

fiber-optic cable

transmit data as pulses of light through tiny tubes of glass;lighter and faster

bluetooth

short range radio communication standard that transmits data over short distances; up to 33 feet

wi-fi

uses high frequency signals to transmit data

microwave

communication uses high-frequency radio waves

WiMax

new standard that extends the range of Wi-Fi networks using microwave connections

celluar

communication uses multiple antennae to send and receive data within relatively small geographic regions

satellite

communication uses satellites orbiting about 22,000 miles above the earth as microwave relay stations

uplink

sending data to a satellite

downlink

receiving data from a satellite

analog signals

continuous electronic waves

digital signals

computers, in contrast, send and receive

DSL - digital subscriber line

is provided by companies using existing telephone lines to provide high-speed connections

ADSL - asymmetric digital subscriber

most widely used types of DSL

bandwidth

a measurement of the width or capacity of the communication channel

protocols

rules for exchanging data between computers

TCP/IP

identifying sending and receiving devices ; breaks up traffic packages into smaller parts and send it

node

any device that is connected to a network

network architecture

describes how a network is arranged and how resources are coordinated and shared

LAN

local area nwtwork located within close proximity

Home

local area network for home and apt use; typically wireless

WLAN

wireless local area network all communication passes through access point

PAN

personal area network; connects digital devices such as PDAs

MAN

metropolitan area network; typically spans cities with coverage up to 100 miles

VAN

wide area network for countrywide or worldwide coverage

star network

each device connected directly to a central network switch

firewall

consists of hardware and software that control access to a company's intranet and other internal networks

proxy server

most use softeare or a special computer

Intrusion detection systems (IDS)

work with firewalls to protect an organization's network

Virtual private networks (VPN)

create a secure private connection between a remote user and an organization;s internal network

privacy

what are the threats to personal privacy, and how can we protect ourselves?

security

how can access to sensitive information be controlled, and how can we secure hardware and software?

ethics

how do the actions of individual users and companies affect society?

freedom of information act

you are also entitled to look at your records held by government agencies

cracker

a computer criminal who creates and distributes malicious programs

viruses

programs that migrate through networks and operating systems, and most attach themselves to different programs and databases

cybercrime/ computer crime

any criminal offense that involves a computer and a network

malware

malicious software

computer fraud and abuse act

creating and knowingly spreading a virus is a very serious crime and a federal offense punishable

worms

programs that simply replicate themselves over and over again

trojan horses

programs that appear to be harmless; however they contain malicious programs; they are NOT viruses

zombies

computers infected by a virus, worm , or trojan horse that allows them to be remotely controlled for malicious purposes

cyberbullying

the use of the internet, smartphones, or other devices to send or post content intended to hurt or embarrass another person

Firewalls

act as a security buffer between a corporation's private network and all external networks, including the internet

encryption

the process of coding information to make it unreadable expect those who have a special piece of information know as an encryption key

email encryption

protects email messages as they move across the internet

file encryption

protects sensitive files by encrypting them before they are stored on a hard drive

website encryption

secured web transactions

supervisors

manage and monitor the employees or workers

middle management

control, planning , and decision management ; long term goals of organization

top management

concerned with long term planning ; they need information to help them with future growth

transaction processing system ( TPS)/ data processing system (DPS)

helps an organization keep track of routine operations and records these events in a database

balance sheets

list the overall financial condition of an organization

income statements

show a company financial performance; income, expenses, and the difference between them for a specific time period

general ledger

keeps track of all summaries of all the foregoing transactions

character

is the most basic logical data element ; a single letter, number, or special character

field

group of related characters ( ex last name )

attribute

description or characteristic

entity

person, place, thing, or object

record

collection of related fields (payroll record)

table

is a collection of related records (payroll table)

sharing

information from one department can be readily shared

security ( databases)

users are given passwords or access only to the kind on information they need

less data redundancy

without a common database, individual departments have to create and maintain their own data, and data redundancy results

data integrity

when there are multiple sources of data, each source may have variations ( main street vs main st. )

relational databases

the data elements are stored in different tables, each of which consists of rows and columns

program

a list of instructions for the computer to follow to accomplish the task of processing data into information

machine language

first generation; 0s and 1s

assembly language

second generation; ( ADD )

high level procedural language

third generation; ( if, then)

task oriented language

fourth generation; english like ;SQUEL

problem and constraint language

fifth generation; english like

computer-aided software engineering (CASE)

provide some automation and assistance in program design, coding, and testing

object-oriented programming (OOP)

a process by which a program is organized into objects

primary key

uniquely identifies the record