Chapter 1 Flashcards
What is the digital revolution?
An ongoing process of social, political, and economic change brought about by digital technology
Digitization
The process of converting text, numbers, sound, photos, and video into data that can be processed by digital devices
What is the significance of digitization?
Things as diverse as books, movies, songs, conversations, documents, and photos can all be distilled down to a common set of signals that do not require separate devices
What is data processing?
Based on input-processing-output cycle
What is personal computing?
Characterized by small, standalone, computers powered by a local software
Local software
Refers to any software that is installed on a computer’s hard drive
What caused the upward swing in computer ownership during the 1990s?
As computers became networked and when the internet became opened to the public
Computer network
A group on computers linked together to share data and resources
Internet
A global computer network originally developed as a military project that was handed over to the National Science Foundation for education and research
Web
(World Wide Web) A collection of linked documents, graphics, and sounds that can be accessed over the Internet
What is cloud computing?
Provides access to information, applications, communications, and storage over the Internet
What is convergence?
A process by which several technologies with distinct functionalities evolve to form a single product
What role do social media play?
Social media are cloud based applications designed for social interaction and consumer-generated content
How does digital technology affect freedom and democracy?
Because it is easier to cross cultural boundaries, anonymizer tools are necessary in some cases
Anonymizer tools
Cloak a person’s identity even make it possible to exercise freedom of speech in situations where reprisals might repress it
Has digital technology changed the way we view privacy?
Social media encourages participants to reveal personal details online, changing our our expectation of what is private and what is not
How does digital technology affect intellectual property?
Digital technology has made it easier to produce copies with no loss in quality from the original.
Intellectual property
Refers to the ownership of certain types of information, ideas, or representations
Open source
Promote copying, free distribution, peer review, and user modification
What effect does digital technology have on the economy?
Digital technology creates a global economy in which consumers gain access to a wide variety of products from all over the globe
Digital divide
A term that refers to the gap between people who have access to technology and those who do not
What is a computer?
A multipurpose device that accepts input, processes data, stores data, and produces output, all according to a series of stored instructions
What is input?
Input is whatever is typed, submitted, or transmitted to a computer system
What is output?
Output is the result produced by a computer
What does “process data” mean?
Data refers to the symbols that represent facts, objects, and ideas. Computers manipulate this data in many ways, known as processing.
CPU
(central processing unit) Where most processing takes place; The CPU of most modern computers is a microprocessor
Microprocessor
An electronic component that can be programmed to perform tasks based on data it receives
How do computers store data?
Computers can hold data in memory or storage. Data is stored in files.
Memory
An area of a computer that temporarily holds data waiting to be processed
Storage
The area where data can be left on a permanent basis when it is not immediately needed for processing
File
A named collection of data that exists on a storage medium such as a hard disk, CD, DVD, or flash drive
What’s so significant about a computer’s ability to store instructions?
A stored program means that a series of instructions for a computing task can be loaded into a computer’s memory and can easily be replaced when it is time for the computer to do a new task.
Computer program
The series of instructions that tells a computer how to carry out processing tasks
Software
Formed by the programs; sets up a computer to do a specific task
What kind of software do computers run?
Application software and system software
Application software
A set of computer programs that helps a person carry out a task. Called apps in handheld devices.
System software
Helps the computer system monitor itself in order to function efficiently. Ex: Operating system
Operating system
The master controller for all the activities that take place within a computer
Are computers categorized in any way?
Personal computers, severs, mainframes, supercomputers
Personal computer
A microprocessor-based computing device designed to meet the computing needs of an individual
Are handheld devices computers?
Handheld devices that allow you to install applications can be classified as personal computers; devices that are not programmable cannot
Is an Xbox a computer?
A videogame console is a computer, but would not generally be referred to as a personal computer because of its history as a dedicated game device
What is a workstation?
A powerful desktop computer used for high-performance tasks that require a lot of processing speed
What makes a computer a server?
The purpose of a server is to serve computers on a network by supplying them with data
Client
Any software or digital device that requests data from a server
Download
Refers to the process of copying a file from a server to your own client computer
Upload
Refers to the process of copying files from your client computer to a server
What’s so special about a mainframe computer?
A mainframe is a large and expensive computer capable of simultaneously processing data for hundreds or thousands of users.
How powerful is a supercomputer?
A computer falls into the supercomputer category if it is, at the time of construction, one of the fastest computers in the world
Compute-intensive
A problem that requires massive amounts of data to be processed using complex mathematical calculations
What is a microcontroller?
A special-purpose microprocessor that is built into the machine it controls
How does a microcontroller work?
Accepts special input and stores this information in memory. The microcontroller processes additional information from the device and responds, as output.
Is a microcontroller really a computer?
Technically yes, but they tend to be referred to as processors
Why are microcontrollers significant?
They can be embedded in all sorts of everyday devices, enabling machine to perform specific tasks that require awareness and feedback from the environment
What is data?
Refers to the symbols that represent people, events, things, and ideas.
Is there a difference between data and information?
Data is used by machines such as computers, while information is used by humans
What is data representation?
Refers to the form in which data is stored, processed, and transmitted
What is the difference between analog and digital?
Digital data is text, numbers, graphics, sound, and video that have been converted into discrete digits such as 0s and 1s,
while analog data is represented using an infinite scale of values
How does digital data work?
Digital signals are represented by two different voltages, such as +5 volts and .2+ volts or light and dark spots etched onto the surface of a CD or hard disk.
Bit
A 0 or 1 used in digital representation of data
How do digital devices represent numbers?
Digital devices represent numerical data, numbers that can be used in arithmetic operations, using the binary system, which consists of the digits 0 and 1
How do digital devices represent words and letters?
Digital devices use character data, which are letters and symbols that are not used in arithmetic operations, such as ASCII, EBCDIC, and Unicode
ASCII
(American Standard Code for Information Interchange) Requires only 7 bits for each character, coding for 128 characters
EBCDIC
(Extended Binary-Coded Decimal Interchange Code) An 8-bit code used by older, mainframe computers
Extended ASCII
A superset of ASCII that uses 8 bits to represent each character, which codes for 256 characters
Unicode
Uses sixteen bits and provides codes for 65,000 characters
How can bits be used to store images?
A image is a series of colored dots and each dot is assigned a binary number according to its color
How can bits be used to store sound?
A sound wave can be sampled at various time intervals and each sample can be recorded as a binary number and stored
How can I tell the difference between bits and bytes?
A bit is one binary digit. A byte is a group of eight. Transmission speeds are usually expressed in bits, whereas storage space is typically expressed in bytes
Kilo, Mega, Giga, Tera, Peta, Exa
2^10, 2^20, 2^30, 2^40, 2^50, 2^60
How do digital devices store and transport all those bits?
Bits take the form of electrical pulses that can travel over circuits
What’s a computer chip?
Technical words for integrated circuit, which is a super-thin slice of semiconducting material packed with microscopic circuit elements
Semiconducting materials
Substances with properties between those of a conductor and an insulator
How do chips fit together?
The system board houses all essential chips and provides connecting circuity between them
How do digital devices process data?
These devices work with data under the control of a computer program
Who creates programs?
Computer programmers crease programs written in high-level programming language
Source code
The human-readable version of a program
How does a source code get converted?
The procedure for translating source code is into 0s and 1s can be accomplished by a complier or an interpreter.
Complier
Converts all the statements in a program in a single batch
Object code
The human-readable collection of instructions that results from a compiler and is placed in a file
Interpreter
An alternative to a complier; Converts and executes one statement at a time while the program is running
Instruction set
The limited set of activities that a microprocessor is hardwired to perform
Machine language
The list of codes for a microprocessor’s instruction set that can be directly executed by the processor’s circuitry
Machine code
A set of machine language instructions for a program which has two parts, an op code and the operand
Op code
(Operation code) Command word for an operation
Operand
Specifies the data or the address of the data for the operation
What happens inside a computer chip?
Different kinds of operational units, such as the ALU and control unit, perform tasks
ALU
(Arithmetic logic unit) Part of the microprocessor that performs arithmetic operations and logical operations; Uses registers to hold data that is being processed
Control Unit
Fetches each instruction from the ALU’s registers
Instruction cycle
Refers to the process in which a computer executes a single instruction
- ) Fetch instruction
- ) Interpret instruction
- ) Execute instruction
- ) Increment pointer to the next instruction
What role does the control unit play?
The control unit fetches the instruction. It can then interpret the instruction, gather the specified data, or tell the ALU to begin processing
When does the ALU swing into action?
When it gets a go signal from the control unit, the ALU processes the data and places the result in an accumulator, where it can be sent to memory or used for further processing
Authentication protocol
Refers to any method that confirms a person’s identity using something the person knows, possesses, or is
Biometrics
A method of identification that involves physical properties
User ID
Series of characters that become a person’s unique identifier
Case sensitive
Differentiates between uppercase and lowercase
Password
A series of characters that verifies a user ID and guarantees that you are the person you claim to be
Identity theft
When someone gains unauthorized access to your personal data and uses it illegally
Dictionary attack
Helps hackers guess your password by using a dictionary that contains thousands of the most commonly used passwords
Brute force attack
A password-cracking software that exhausts all possible combinations of letters to decrypt a password
Sniffing
Intercepts information sent out over a network
Phishing
An approach in which a hacker poses as a legitimate representative of an official organization and persuades you to disclose highly confidential information
Keylogger
A software that secretly records a user’s keystrokes and sends the information to a hacker; Form of a malicious code called a Trojan horse
Password manager
stores user IDs with their corresponding passwords and automatically fills in login forms
Password manager software
Software application that feeds passwords into login forms regardless of the software you’re using
